Programs & Examples On #Check constraint

numpy matrix vector multiplication

Simplest solution

Use numpy.dot or a.dot(b). See the documentation here.

>>> a = np.array([[ 5, 1 ,3], 
                  [ 1, 1 ,1], 
                  [ 1, 2 ,1]])
>>> b = np.array([1, 2, 3])
>>> print a.dot(b)
array([16, 6, 8])

This occurs because numpy arrays are not matrices, and the standard operations *, +, -, / work element-wise on arrays. Instead, you could try using numpy.matrix, and * will be treated like matrix multiplication.


Other Solutions

Also know there are other options:

  • As noted below, if using python3.5+ the @ operator works as you'd expect:

    >>> print(a @ b)
    array([16, 6, 8])
    
  • If you want overkill, you can use numpy.einsum. The documentation will give you a flavor for how it works, but honestly, I didn't fully understand how to use it until reading this answer and just playing around with it on my own.

    >>> np.einsum('ji,i->j', a, b)
    array([16, 6, 8])
    
  • As of mid 2016 (numpy 1.10.1), you can try the experimental numpy.matmul, which works like numpy.dot with two major exceptions: no scalar multiplication but it works with stacks of matrices.

    >>> np.matmul(a, b)
    array([16, 6, 8])
    
  • numpy.inner functions the same way as numpy.dot for matrix-vector multiplication but behaves differently for matrix-matrix and tensor multiplication (see Wikipedia regarding the differences between the inner product and dot product in general or see this SO answer regarding numpy's implementations).

    >>> np.inner(a, b)
    array([16, 6, 8])
    
    # Beware using for matrix-matrix multiplication though!
    >>> b = a.T
    >>> np.dot(a, b)
    array([[35,  9, 10],
           [ 9,  3,  4],
           [10,  4,  6]])
    >>> np.inner(a, b) 
    array([[29, 12, 19],
           [ 7,  4,  5],
           [ 8,  5,  6]])
    

Rarer options for edge cases

  • If you have tensors (arrays of dimension greater than or equal to one), you can use numpy.tensordot with the optional argument axes=1:

    >>> np.tensordot(a, b, axes=1)
    array([16,  6,  8])
    
  • Don't use numpy.vdot if you have a matrix of complex numbers, as the matrix will be flattened to a 1D array, then it will try to find the complex conjugate dot product between your flattened matrix and vector (which will fail due to a size mismatch n*m vs n).

Recommended way to get hostname in Java

As others have noted, getting the hostname based on DNS resolution is unreliable.

Since this question is unfortunately still relevant in 2018, I'd like to share with you my network-independent solution, with some test runs on different systems.

The following code tries to do the following:

  • On Windows

    1. Read the COMPUTERNAME environment variable through System.getenv().

    2. Execute hostname.exe and read the response

  • On Linux

    1. Read the HOSTNAME environment variable through System.getenv()

    2. Execute hostname and read the response

    3. Read /etc/hostname (to do this I'm executing cat since the snippet already contains code to execute and read. Simply reading the file would be better, though).

The code:

public static void main(String[] args) throws IOException {
    String os = System.getProperty("os.name").toLowerCase();

    if (os.contains("win")) {
        System.out.println("Windows computer name through env:\"" + System.getenv("COMPUTERNAME") + "\"");
        System.out.println("Windows computer name through exec:\"" + execReadToString("hostname") + "\"");
    } else if (os.contains("nix") || os.contains("nux") || os.contains("mac os x")) {
        System.out.println("Unix-like computer name through env:\"" + System.getenv("HOSTNAME") + "\"");
        System.out.println("Unix-like computer name through exec:\"" + execReadToString("hostname") + "\"");
        System.out.println("Unix-like computer name through /etc/hostname:\"" + execReadToString("cat /etc/hostname") + "\"");
    }
}

public static String execReadToString(String execCommand) throws IOException {
    try (Scanner s = new Scanner(Runtime.getRuntime().exec(execCommand).getInputStream()).useDelimiter("\\A")) {
        return s.hasNext() ? s.next() : "";
    }
}

Results for different operating systems:

macOS 10.13.2

Unix-like computer name through env:"null"
Unix-like computer name through exec:"machinename
"
Unix-like computer name through /etc/hostname:""

OpenSuse 13.1

Unix-like computer name through env:"machinename"
Unix-like computer name through exec:"machinename
"
Unix-like computer name through /etc/hostname:""

Ubuntu 14.04 LTS This one is kinda strange since echo $HOSTNAME returns the correct hostname, but System.getenv("HOSTNAME") does not:

Unix-like computer name through env:"null"
Unix-like computer name through exec:"machinename
"
Unix-like computer name through /etc/hostname:"machinename
"

EDIT: According to legolas108, System.getenv("HOSTNAME") works on Ubuntu 14.04 if you run export HOSTNAME before executing the Java code.

Windows 7

Windows computer name through env:"MACHINENAME"
Windows computer name through exec:"machinename
"

Windows 10

Windows computer name through env:"MACHINENAME"
Windows computer name through exec:"machinename
"

The machine names have been replaced but I kept the capitalization and structure. Note the extra newline when executing hostname, you might have to take it into account in some cases.

Using textures in THREE.js

By the time the image is loaded, the renderer has already drawn the scene, hence it is too late. The solution is to change

texture = THREE.ImageUtils.loadTexture('crate.gif'),

into

texture = THREE.ImageUtils.loadTexture('crate.gif', {}, function() {
    renderer.render(scene);
}),

jQuery - on change input text

That is working for me. Could be a browser issue as mentioned, or maybe jQuery isn't registered properly, or perhaps the real issue is more complicated (that you made a simpler version to ask this). PS - did have to click out of the text box to make it fire.

http://jsfiddle.net/toddhd/Qt7fH/

php timeout - set_time_limit(0); - don't work

This is an old thread, but I thought I would post this link, as it helped me quite a bit on this issue. Essentially what it's saying is the server configuration can override the php config. From the article:

For example mod_fastcgi has an option called "-idle-timeout" which controls the idle time of the script. So if the script does not output anything to the fastcgi handler for that many seconds then fastcgi would terminate it. The setup is somewhat like this:

Apache <-> mod_fastcgi <-> php processes

The article has other examples and further explanation. Hope this helps somebody else.

The transaction log for the database is full

The following will truncate the log.

USE [yourdbname] 
GO

-- TRUNCATE TRANSACTION LOG --
DBCC SHRINKFILE(yourdbname_log, 1)
BACKUP LOG yourdbname WITH TRUNCATE_ONLY
DBCC SHRINKFILE(yourdbname_log, 1)
GO

-- CHECK DATABASE HEALTH --
ALTER FUNCTION [dbo].[checker]() RETURNS int AS BEGIN  RETURN 0 END
GO

What is the use of <<<EOD in PHP?

there are four types of strings available in php. They are single quotes ('), double quotes (") and Nowdoc (<<<'EOD') and heredoc(<<<EOD) strings

you can use both single quotes and double quotes inside heredoc string. Variables will be expanded just as double quotes.

nowdoc strings will not expand variables just like single quotes.

ref: http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc

Linux c++ error: undefined reference to 'dlopen'

 $gcc -o program program.c -l <library_to_resolve_program.c's_unresolved_symbols>

A good description of why the placement of -l dl matters

But there's also a pretty succinct explanation in the docs From $man gcc

   -llibrary
   -l library
       Search the library named library when linking.  (The second
       alternative with the library as a separate argument is only for POSIX
       compliance and is not recommended.)
       It makes a difference where in the command you write this option; the
       linker searches and processes libraries and object files in the order
       they are specified.  Thus, foo.o -lz bar.o searches library z after
       file foo.o but before bar.o.  If bar.o refers to functions in z,
       those functions may not be loaded.

Bootstrap 3 Multi-column within a single ul not floating properly

Thanks, Varun Rathore. It works perfectly!

For those who want graceful collapse from 4 items per row to 2 items per row depending on the screen width:

<ul class="list-group row">
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_1</li>
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_2</li>
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_3</li>
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_4</li>
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_5</li>
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_6</li>
    <li class="list-group-item col-xs-6 col-sm-4 col-md-3">Cell_7</li>
</ul>

How would I run an async Task<T> method synchronously?

use below code snip

Task.WaitAll(Task.Run(async () => await service.myAsyncMethod()));

Changing ViewPager to enable infinite page scrolling

Its hacked by CustomPagerAdapter:

MainActivity.java:

import android.content.Context;
import android.os.Handler;
import android.os.Parcelable;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private List<String> numberList = new ArrayList<String>();
    private CustomPagerAdapter mCustomPagerAdapter;
    private ViewPager mViewPager;
    private Handler handler;
    private Runnable runnable;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        numberList.clear();
        for (int i = 0; i < 10; i++) {
        numberList.add(""+i);
        }

        mViewPager = (ViewPager)findViewById(R.id.pager);
        mCustomPagerAdapter = new CustomPagerAdapter(MainActivity.this);
        EndlessPagerAdapter mAdapater = new EndlessPagerAdapter(mCustomPagerAdapter);
        mViewPager.setAdapter(mAdapater);


        mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                int modulo = position%numberList.size();
                Log.i("Current ViewPager View's Position", ""+modulo);

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

        handler = new Handler();
        runnable = new Runnable() {
            @Override
            public void run() {

                mViewPager.setCurrentItem(mViewPager.getCurrentItem()+1);
                handler.postDelayed(runnable, 1000);
            }
        };

        handler.post(runnable);

    }

    @Override
    protected void onDestroy() {
        if(handler!=null){
            handler.removeCallbacks(runnable);
        }
        super.onDestroy();
    }

    private class CustomPagerAdapter extends PagerAdapter {

        Context mContext;
        LayoutInflater mLayoutInflater;

        public CustomPagerAdapter(Context context) {
            mContext = context;
            mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

        @Override
        public int getCount() {
            return numberList.size();
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == ((LinearLayout) object);
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            View itemView = mLayoutInflater.inflate(R.layout.row_item_viewpager, container, false);

            TextView textView = (TextView) itemView.findViewById(R.id.txtItem);
            textView.setText(numberList.get(position));
            container.addView(itemView);
            return itemView;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((LinearLayout) object);
        }
    }

    private class EndlessPagerAdapter extends PagerAdapter {

        private static final String TAG = "EndlessPagerAdapter";
        private static final boolean DEBUG = false;

        private final PagerAdapter mPagerAdapter;

        EndlessPagerAdapter(PagerAdapter pagerAdapter) {
            if (pagerAdapter == null) {
                throw new IllegalArgumentException("Did you forget initialize PagerAdapter?");
            }
            if ((pagerAdapter instanceof FragmentPagerAdapter || pagerAdapter instanceof FragmentStatePagerAdapter) && pagerAdapter.getCount() < 3) {
                throw new IllegalArgumentException("When you use FragmentPagerAdapter or FragmentStatePagerAdapter, it only supports >= 3 pages.");
            }
            mPagerAdapter = pagerAdapter;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            if (DEBUG) Log.d(TAG, "Destroy: " + getVirtualPosition(position));
            mPagerAdapter.destroyItem(container, getVirtualPosition(position), object);

            if (mPagerAdapter.getCount() < 4) {
                mPagerAdapter.instantiateItem(container, getVirtualPosition(position));
            }
        }

        @Override
        public void finishUpdate(ViewGroup container) {
            mPagerAdapter.finishUpdate(container);
        }

        @Override
        public int getCount() {
            return Integer.MAX_VALUE; // this is the magic that we can scroll infinitely.
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mPagerAdapter.getPageTitle(getVirtualPosition(position));
        }

        @Override
        public float getPageWidth(int position) {
            return mPagerAdapter.getPageWidth(getVirtualPosition(position));
        }

        @Override
        public boolean isViewFromObject(View view, Object o) {
            return mPagerAdapter.isViewFromObject(view, o);
        }

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            if (DEBUG) Log.d(TAG, "Instantiate: " + getVirtualPosition(position));
            return mPagerAdapter.instantiateItem(container, getVirtualPosition(position));
        }

        @Override
        public Parcelable saveState() {
            return mPagerAdapter.saveState();
        }

        @Override
        public void restoreState(Parcelable state, ClassLoader loader) {
            mPagerAdapter.restoreState(state, loader);
        }

        @Override
        public void startUpdate(ViewGroup container) {
            mPagerAdapter.startUpdate(container);
        }

        int getVirtualPosition(int realPosition) {
            return realPosition % mPagerAdapter.getCount();
        }

        PagerAdapter getPagerAdapter() {
            return mPagerAdapter;
        }

    }
}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="180dp">
    </android.support.v4.view.ViewPager>

</RelativeLayout>

row_item_viewpager.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent"
    android:gravity="center">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtItem"
        android:textAppearance="@android:style/TextAppearance.Large"/>

</LinearLayout>

Done

DataTables fixed headers misaligned with columns in wide tables

EDIT: See the latest Fiddle with "fixed header":


The Fiddle.

One of the solutions is to implement scrolling yourself instead of letting DataTables plugin do it for you.

I've taken your example and commented out sScrollX option. When this option is not present DataTables plugin will simply put your table as is into a container div. This table will stretch out of the screen, therefore, to fix that we can put it into a div with required width and an overflow property set - this is exactly what the last jQuery statement does - it wraps existing table into a 300px wide div. You probably will not need to set the width on the wrapping div at all (300px in this example), I have it here so that clipping effect is easily visible. And be nice, don't forget to replace that inline style with a class.

$(document).ready(function() {
var stdTable1 = $(".standard-grid1").dataTable({
    "iDisplayLength": -1,
    "bPaginate": true,
    "iCookieDuration": 60,
    "bStateSave": false,
    "bAutoWidth": false,
    //true
    "bScrollAutoCss": true,
    "bProcessing": true,
    "bRetrieve": true,
    "bJQueryUI": true,
    //"sDom": 't',
    "sDom": '<"H"CTrf>t<"F"lip>',
    "aLengthMenu": [[25, 50, 100, -1], [25, 50, 100, "All"]],
    //"sScrollY": "500px",
    //"sScrollX": "100%",
    "sScrollXInner": "110%",
    "fnInitComplete": function() {
        this.css("visibility", "visible");
    }
});

var tableId = 'PeopleIndexTable';
$('<div style="width: 300px; overflow: auto"></div>').append($('#' + tableId)).insertAfter($('#' + tableId + '_wrapper div').first())});

What is the best way to extract the first word from a string in Java?

String anotherPalindrome = "Niagara. O roar again!"; 
String roar = anotherPalindrome.substring(11, 15); 

You can also do like these

OCI runtime exec failed: exec failed: (...) executable file not found in $PATH": unknown

I was running into this issue and it turned out that I needed to do this:

docker run ${image_name} bash -c "${command}"

Hope that helps someone who finds this error.

Insert new column into table in sqlite?

You have two options. First, you could simply add a new column with the following:

ALTER TABLE {tableName} ADD COLUMN COLNew {type};

Second, and more complicatedly, but would actually put the column where you want it, would be to rename the table:

ALTER TABLE {tableName} RENAME TO TempOldTable;

Then create the new table with the missing column:

CREATE TABLE {tableName} (name TEXT, COLNew {type} DEFAULT {defaultValue}, qty INTEGER, rate REAL);

And populate it with the old data:

INSERT INTO {tableName} (name, qty, rate) SELECT name, qty, rate FROM TempOldTable;

Then delete the old table:

DROP TABLE TempOldTable;

I'd much prefer the second option, as it will allow you to completely rename everything if need be.

Modulo operation with negative numbers

The other answers have explained in C99 or later, division of integers involving negative operands always truncate towards zero.

Note that, in C89, whether the result round upward or downward is implementation-defined. Because (a/b) * b + a%b equals a in all standards, the result of % involving negative operands is also implementation-defined in C89.

PHP: How to handle <![CDATA[ with SimpleXMLElement?

This is working perfect for me.

$content = simplexml_load_string(
    $raw_xml
    , null
    , LIBXML_NOCDATA
);

Why does the 'int' object is not callable error occur when using the sum() function?

In the interpreter its easy to restart it and fix such problems. If you don't want to restart the interpreter, there is another way to fix it:

Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> l = [1,2,3]
>>> sum(l)
6
>>> sum = 0 # oops! shadowed a builtin!
>>> sum(l)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not callable
>>> import sys
>>> sum = sys.modules['__builtin__'].sum # -- fixing sum
>>> sum(l)
6

This also comes in handy if you happened to assign a value to any other builtin, like dict or list

PHPExcel - set cell type before writing a value in it

The same way as you'd set the type (number format mask) after writing a value to it:

$objPHPExcel->getActiveSheet()
    ->getStyle('A1')
    ->getNumberFormat()
    ->setFormatCode(
        PHPExcel_Style_NumberFormat::FORMAT_GENERAL
    );

or

$objPHPExcel->getActiveSheet()
    ->getStyle('A1')
    ->getNumberFormat()
    ->setFormatCode(
        PHPExcel_Style_NumberFormat::FORMAT_TEXT
    );

Though "Number" isn't a valid format mask.

You can find a list of pre-defined format masks in Classes/PHPExcel/Style/NumberFormat.php or set the value to any valid Excel number format masking string.

Disable Required validation attribute under certain circumstances

I was having this problem when I creating a Edit View for my Model and I want to update just one field.

My solution for a simplest way is put the two field using :

 <%: Html.HiddenFor(model => model.ID) %>
 <%: Html.HiddenFor(model => model.Name)%>
 <%: Html.HiddenFor(model => model.Content)%>
 <%: Html.TextAreaFor(model => model.Comments)%>

Comments is the field that I only update in Edit View, that not have Required Attribute.

ASP.NET MVC 3 Entity

Function in JavaScript that can be called only once

Trying to use underscore "once" function:

var initialize = _.once(createApplication);
initialize();
initialize();
// Application is only created once.

http://underscorejs.org/#once

No suitable driver found for 'jdbc:mysql://localhost:3306/mysql

( If your url is correct and still get that error messege ) Do following steps to setup the Classpath in netbeans,

  1. Create a new folder in your project workspace and add the downloaded .jar file(eg:- mysql-connector-java-5.1.35-bin.jar )
  2. Right click your project > properties > Libraries > ADD jar/Folder Select the jar file in that folder you just make. And click OK.

Now you will see that .jar file will be included under the libraries. Now you will not need to use the line, Class.forName("com.mysql.jdbc.Driver"); also.

If above method did not work, check the mysql-connector version (eg:- 5.1.35) and try a newer or a suitable version for you.

Oracle SQL Developer spool output?

You can export the query results to a text file (or insert statements, or even pdf) by right-clicking on Query Result row (any row) and choose Export

using Sql Developer 3.0

See SQL Developer downloads for latest versions

Remove a child with a specific attribute, in SimpleXML for PHP

Even though SimpleXML doesn't have a detailed way to remove elements, you can remove elements from SimpleXML by using PHP's unset(). The key to doing this is managing to target the desired element. At least one way to do the targeting is using the order of the elements. First find out the order number of the element you want to remove (for example with a loop), then remove the element:

$target = false;
$i = 0;
foreach ($xml->seg as $s) {
  if ($s['id']=='A12') { $target = $i; break; }
  $i++;
}
if ($target !== false) {
  unset($xml->seg[$target]);
}

You can even remove multiple elements with this, by storing the order number of target items in an array. Just remember to do the removal in a reverse order (array_reverse($targets)), because removing an item naturally reduces the order number of the items that come after it.

Admittedly, it's a bit of a hackaround, but it seems to work fine.

What is the Windows equivalent of the diff command?

Well, on Windows I happily run diff and many other of the GNU tools. You can do it with cygwin, but I personally prefer GnuWin32 because it is a much lighter installation experience.

So, my answer is that the Windows equivalent of diff, is none other than diff itself!

Import data.sql MySQL Docker Container

Mount your sql-dump under/docker-entrypoint-initdb.d/yourdump.sql utilizing a volume mount

mysql:
  image: mysql:latest
  container_name: mysql-container
  ports:
    - 3306:3306
  volumes:
    - ./dump.sql:/docker-entrypoint-initdb.d/dump.sql
  environment:
    MYSQL_ROOT_PASSWORD: secret
    MYSQL_DATABASE: name_db
    MYSQL_USER: user
    MYSQL_PASSWORD: password

This will trigger an import of the sql-dump during the start of the container, see https://hub.docker.com/_/mysql/ under "Initializing a fresh instance"

Facebook key hash does not match any stored key hashes

Here is Nice Solution for macOs And It works for me :

keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

Here key store password should be android . Thanks

Passing array in GET for a REST call

Another way of doing that, which can make sense depending on your server architecture/framework of choice, is to repeat the same argument over and over again. Something like this:

/appointments?users=id1&users=id2

In this case I recommend using the parameter name in singular:

/appointments?user=id1&user=id2

This is supported natively by frameworks such as Jersey (for Java). Take a look on this question for more details.

Symfony2 Setting a default choice field selection

If you want to pass in an array of Doctrine entities, try something like this (Symfony 3.0+):

protected $entities;
protected $selectedEntities;

public function __construct($entities = null, $selectedEntities = null)
{
    $this->entities = $entities;
    $this->selectedEntities = $selectedEntities;
}

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder->add('entities', 'entity', [
        'class' => 'MyBundle:MyEntity',
        'choices' => $this->entities,
        'property' => 'id',
        'multiple' => true,
        'expanded' => true,
        'data' => $this->selectedEntities,
    ]);
}

QComboBox - set selected item based on the item's data

You lookup the value of the data with findData() and then use setCurrentIndex()

QComboBox* combo = new QComboBox;
combo->addItem("100",100.0);    // 2nd parameter can be any Qt type
combo->addItem .....

float value=100.0;
int index = combo->findData(value);
if ( index != -1 ) { // -1 for not found
   combo->setCurrentIndex(index);
}

Xcode stuck on Indexing

For me, I made a stupid mistake. I write a Class like this:

class A: A {
.......
}

A class inherit itself that causes the freezing. There is no message hint from Xcode.

What is the "continue" keyword and how does it work in Java?

If you think of the body of a loop as a subroutine, continue is sort of like return. The same keyword exists in C, and serves the same purpose. Here's a contrived example:

for(int i=0; i < 10; ++i) {
  if (i % 2 == 0) {
    continue;
  }
  System.out.println(i);
}

This will print out only the odd numbers.

sequelize findAll sort order in nodejs

I don't think this is possible in Sequelize's order clause, because as far as I can tell, those clauses are meant to be binary operations applicable to every element in your list. (This makes sense, too, as it's generally how sorting a list works.)

So, an order clause can do something like order a list by recursing over it asking "which of these 2 elements is older?" Whereas your ordering is not reducible to a binary operation (compare_bigger(1,2) => 2) but is just an arbitrary sequence (2,4,11,2,9,0).

When I hit this issue with findAll, here was my solution (sub in your returned results for numbers):

var numbers = [2, 20, 23, 9, 53];
var orderIWant = [2, 23, 20, 53, 9];
orderIWant.map(x => { return numbers.find(y => { return y === x })});

Which returns [2, 23, 20, 53, 9]. I don't think there's a better tradeoff we can make. You could iterate in place over your ordered ids with findOne, but then you're doing n queries when 1 will do.

Get div height with plain JavaScript

One option would be

const styleElement = getComputedStyle(document.getElementById("myDiv"));
console.log(styleElement.height);

Java BigDecimal: Round to the nearest whole value

You can use setScale() to reduce the number of fractional digits to zero. Assuming value holds the value to be rounded:

BigDecimal scaled = value.setScale(0, RoundingMode.HALF_UP);
System.out.println(value + " -> " + scaled);

Using round() is a bit more involved as it requires you to specify the number of digits to be retained. In your examples this would be 3, but this is not valid for all values:

BigDecimal rounded = value.round(new MathContext(3, RoundingMode.HALF_UP));
System.out.println(value + " -> " + rounded);

(Note that BigDecimal objects are immutable; both setScale and round will return a new object.)

Get pixel's RGB using PIL

An alternative to converting the image is to create an RGB index from the palette.

from PIL import Image

def chunk(seq, size, groupByList=True):
    """Returns list of lists/tuples broken up by size input"""
    func = tuple
    if groupByList:
        func = list
    return [func(seq[i:i + size]) for i in range(0, len(seq), size)]


def getPaletteInRgb(img):
    """
    Returns list of RGB tuples found in the image palette
    :type img: Image.Image
    :rtype: list[tuple]
    """
    assert img.mode == 'P', "image should be palette mode"
    pal = img.getpalette()
    colors = chunk(pal, 3, False)
    return colors

# Usage
im = Image.open("image.gif")
pal = getPalletteInRgb(im)

How to specify names of columns for x and y when joining in dplyr?

This feature has been added in dplyr v0.3. You can now pass a named character vector to the by argument in left_join (and other joining functions) to specify which columns to join on in each data frame. With the example given in the original question, the code would be:

left_join(test_data, kantrowitz, by = c("first_name" = "name"))

Update GCC on OSX

You can have multiple versions of GCC on your box, to select the one you want to use call it with full path, e.g. instead of g++ use full path /usr/bin/g++ on command line (depends where your gcc lives).

For compiling projects it depends what system do you use, I'm not sure about Xcode (I'm happy with default atm) but when you use Makefiles you can set GXX=/usr/bin/g++ and so on.

EDIT

There's now a xcrun script that can be queried to select appropriate version of build tools on mac. Apart from man xcrun I've googled this explanation about xcode and command line tools which pretty much summarizes how to use it.

Laravel Eloquent - distinct() and count() not working properly together

Based on Laravel docs for raw queries I was able to get count for a select field to work with this code in the product model.

public function scopeShowProductCount($query)
{
    $query->select(DB::raw('DISTINCT pid, COUNT(*) AS count_pid'))
          ->groupBy('pid')
          ->orderBy('count_pid', 'desc');
}

This facade worked to get the same result in the controller:

$products = DB::table('products')->select(DB::raw('DISTINCT pid, COUNT(*) AS count_pid'))->groupBy('pid')->orderBy('count_pid', 'desc')->get();

The resulting dump for both queries was as follows:

#attributes: array:2 [
  "pid" => "1271"
  "count_pid" => 19
],
#attributes: array:2 [
  "pid" => "1273"
  "count_pid" => 12
],
#attributes: array:2 [
  "pid" => "1275"
  "count_pid" => 7
]

android.content.res.Resources$NotFoundException: String resource ID Fatal Exception in Main

You are trying to set int value to TextView so you are getting this issue. To solve this try below one option

option 1:

tv.setText(no+"");

Option2:

tv.setText(String.valueOf(no));

What is the difference between null and System.DBNull.Value?

DataRow has a method that is called IsNull() that you can use to test the column if it has a null value - regarding to the null as it's seen by the database.

DataRow["col"]==null will allways be false.

use

DataRow r;
if (r.IsNull("col")) ...

instead.

How do you get AngularJS to bind to the title attribute of an A tag?

Look at the fiddle here for a quick answer

data-ng-attr-title="{{d.age > 5 ? 'My age is greater than threshold': ''}}"

Displays Title over elements conditionally using Angular JS

Why can't I push to this bare repository?

This related question's answer provided the solution for me... it was just a dumb mistake:

Remember to commit first!

https://stackoverflow.com/a/7572252

If you have not yet committed to your local repo, there is nothing to push, but the Git error message you get back doesn't help you too much.

Backporting Python 3 open(encoding="utf-8") to Python 2

1. To get an encoding parameter in Python 2:

If you only need to support Python 2.6 and 2.7 you can use io.open instead of open. io is the new io subsystem for Python 3, and it exists in Python 2,6 ans 2.7 as well. Please be aware that in Python 2.6 (as well as 3.0) it's implemented purely in python and very slow, so if you need speed in reading files, it's not a good option.

If you need speed, and you need to support Python 2.6 or earlier, you can use codecs.open instead. It also has an encoding parameter, and is quite similar to io.open except it handles line-endings differently.

2. To get a Python 3 open() style file handler which streams bytestrings:

open(filename, 'rb')

Note the 'b', meaning 'binary'.

How can I get date and time formats based on Culture Info?

You can retrieve the format strings from the CultureInfo DateTimeFormat property, which is a DateTimeFormatInfo instance. This in turn has properties like ShortDatePattern and ShortTimePattern, containing the format strings:

CultureInfo us = new CultureInfo("en-US");
string shortUsDateFormatString = us.DateTimeFormat.ShortDatePattern;
string shortUsTimeFormatString = us.DateTimeFormat.ShortTimePattern;

CultureInfo uk = new CultureInfo("en-GB");
string shortUkDateFormatString = uk.DateTimeFormat.ShortDatePattern;
string shortUkTimeFormatString = uk.DateTimeFormat.ShortTimePattern;

If you simply want to format the date/time using the CultureInfo, pass it in as your IFormatter when converting the DateTime to a string, using the ToString method:

string us = myDate.ToString(new CultureInfo("en-US"));
string uk = myDate.ToString(new CultureInfo("en-GB"));

Why can't non-default arguments follow default arguments?

Required arguments (the ones without defaults), must be at the start to allow client code to only supply two. If the optional arguments were at the start, it would be confusing:

fun1("who is who", 3, "jack")

What would that do in your first example? In the last, x is "who is who", y is 3 and a = "jack".

lodash multi-column sortBy descending

In the documentation of the version 4.11.x, says: ` "This method is like _.sortBy except that it allows specifying the sort orders of the iteratees to sort by. If orders is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values." (source https://lodash.com/docs/4.17.10#orderBy)

let sorted = _.orderBy(this.items, ['fieldFoo', 'fieldBar'], ['asc', 'desc'])

belongs_to through associations

It sounds like what you want is a User who has many Questions.
The Question has many Answers, one of which is the User's Choice.

Is this what you are after?

I would model something like that along these lines:

class User
  has_many :questions
end

class Question
  belongs_to :user
  has_many   :answers
  has_one    :choice, :class_name => "Answer"

  validates_inclusion_of :choice, :in => lambda { answers }
end

class Answer
  belongs_to :question
end

From inside of a Docker container, how do I connect to the localhost of the machine?

I disagree with the answer from Thomasleveil.

Making mysql bind to 172.17.42.1 will prevent other programs using the database on the host to reach it. This will only work if all your database users are dockerized.

Making mysql bind to 0.0.0.0 will open the db to outside world, which is not only a very bad thing to do, but also contrary to what the original question author wants to do. He explicitly says "The MySql is running on localhost and not exposing a port to the outside world, so its bound on localhost"

To answer the comment from ivant

"Why not bind mysql to docker0 as well?"

This is not possible. The mysql/mariadb documentation explicitly says it is not possible to bind to several interfaces. You can only bind to 0, 1, or all interfaces.

As a conclusion, I have NOT found any way to reach the (localhost only) database on the host from a docker container. That definitely seems like a very very common pattern, but I don't know how to do it.

jQuery if statement to check visibility

After fixing a performance issue related to the use of .is(":visible"), I would recommend against the above answers and instead use jQuery's code for deciding whether a single element is visible:

$.expr.filters.visible($("#singleElementID")[0]);

What .is does is check whether a set of elements is within another set of elements. So you will looking for your element within the entire set of visible elements on your page. Having 100 elements is pretty normal and might take a few milliseconds to search through the array of visible elements. If you're building a web app you probably have hundreds or possibly thousands. Our app was sometimes taking 100ms for $("#selector").is(":visible") since it was checking if an element was in an array of 5000 other elements.

VBA Date as integer

Date is not an Integer in VB(A), it is a Double.

You can get a Date's value by passing it to CDbl().

CDbl(Now())      ' 40877.8052662037 

From the documentation:

The 1900 Date System

In the 1900 date system, the first day that is supported is January 1, 1900. When you enter a date, the date is converted into a serial number that represents the number of elapsed days starting with 1 for January 1, 1900. For example, if you enter July 5, 1998, Excel converts the date to the serial number 35981.

So in the 1900 system, 40877.805... represents 40,876 days after January 1, 1900 (29 November 2011), and ~80.5% of one day (~19:19h). There is a setting for 1904-based system in Excel, numbers will be off when this is in use (that's a per-workbook setting).

To get the integer part, use

Int(CDbl(Now())) ' 40877

which would return a LongDouble with no decimal places (i.e. what Floor() would do in other languages).

Using CLng() or Round() would result in rounding, which will return a "day in the future" when called after 12:00 noon, so don't do that.

How to write to a file without overwriting current contents?

Instead of "w" use "a" (append) mode with open function:

with open("games.txt", "a") as text_file:

Node.js, can't open files. Error: ENOENT, stat './path/to/file'

Paths specified with a . are relative to the current working directory, not relative to the script file. So the file might be found if you run node app.js but not if you run node folder/app.js. The only exception to this is require('./file') and that is only possible because require exists per-module and thus knows what module it is being called from.

To make a path relative to the script, you must use the __dirname variable.

var path = require('path');

path.join(__dirname, 'path/to/file')

or potentially

path.join(__dirname, 'path', 'to', 'file')

jQuery UI Dialog window loaded within AJAX style jQuery UI Tabs

curious - why doesn't the 'nothing easier than this' answer (above) not work? it looks logical? http://206.251.38.181/jquery-learn/ajax/iframe.html

Another Repeated column in mapping for entity error

Take care to provide only 1 setter and getter for any attribute. The best way to approach is to write down the definition of all the attributes then use eclipse generate setter and getter utility rather than doing it manually. The option comes on right click-> source -> Generate Getter and Setter.

How to call a button click event from another method

For people wondering, this also works for button click. For example:

private void btn_Click(object sender, EventArgs e)
        {
            MessageBox.Show("Test")
        }

private void txb_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char)13)
            {
                btn_Click(sender, e);
            }

When pressing Enter in the textfield(txb) in this case it will click the button which will active the MessageBox.

Android load from URL to Bitmap

Please try this following steps.

1) Create AsyncTask in class or adapter(if you want to change the list item image).

public class AsyncTaskLoadImage extends AsyncTask<String, String, Bitmap> {
        private final static String TAG = "AsyncTaskLoadImage";
        private ImageView imageView;

        public AsyncTaskLoadImage(ImageView imageView) {
            this.imageView = imageView;
        }

        @Override
        protected Bitmap doInBackground(String... params) {
            Bitmap bitmap = null;
            try {
                URL url = new URL(params[0]);
                bitmap = BitmapFactory.decodeStream((InputStream) url.getContent());
            } catch (IOException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return bitmap;
        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            try {
                int width, height;
                height = bitmap.getHeight();
                width = bitmap.getWidth();

                Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
                Canvas c = new Canvas(bmpGrayscale);
                Paint paint = new Paint();
                ColorMatrix cm = new ColorMatrix();
                cm.setSaturation(0);
                ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
                paint.setColorFilter(f);
                c.drawBitmap(bitmap, 0, 0, paint);
                imageView.setImageBitmap(bmpGrayscale);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

2) Call the AsyncTask from your activity, fragment or adapter(inside onBindViewHolder).

2.a) For adapter:

    String src = current.getProductImage();
    new AsyncTaskLoadImage(holder.icon).execute(src);

2.b) For activity and fragment:

**Activity:**
  ImageView imagview= (ImageView) findViewById(R.Id.imageview);
  String src = (your image string);
  new AsyncTaskLoadImage(imagview).execute(src);

**Fragment:**
  ImageView imagview= (ImageView)view.findViewById(R.Id.imageview);
  String src = (your image string);
  new AsyncTaskLoadImage(imagview).execute(src);

3) Kindly run the app and check the image.

Happy coding....:)

Location of Django logs and errors

Add to your settings.py:

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'file': {
            'level': 'DEBUG',
            'class': 'logging.FileHandler',
            'filename': 'debug.log',
        },
    },
    'loggers': {
        'django': {
            'handlers': ['file'],
            'level': 'DEBUG',
            'propagate': True,
        },
    },
}

And it will create a file called debug.log in the root of your. https://docs.djangoproject.com/en/1.10/topics/logging/

How do I get the RootViewController from a pushed controller?

Swift version :

var rootViewController = self.navigationController?.viewControllers.first

ObjectiveC version :

UIViewController *rootViewController = [self.navigationController.viewControllers firstObject];

Where self is an instance of a UIViewController embedded in a UINavigationController.

How to set default vim colorscheme

Copy downloaded color schemes to ~/.vim/colors/Your_Color_Scheme.

Then write

colo Your_Color_Scheme

or

colorscheme Your_Color_Scheme

into your ~/.vimrc.

See this link for holokai

Passing arrays as parameters in bash

With a few tricks you can actually pass named parameters to functions, along with arrays.

The method I developed allows you to access parameters passed to a function like this:

testPassingParams() {

    @var hello
    l=4 @array anArrayWithFourElements
    l=2 @array anotherArrayWithTwo
    @var anotherSingle
    @reference table   # references only work in bash >=4.3
    @params anArrayOfVariedSize

    test "$hello" = "$1" && echo correct
    #
    test "${anArrayWithFourElements[0]}" = "$2" && echo correct
    test "${anArrayWithFourElements[1]}" = "$3" && echo correct
    test "${anArrayWithFourElements[2]}" = "$4" && echo correct
    # etc...
    #
    test "${anotherArrayWithTwo[0]}" = "$6" && echo correct
    test "${anotherArrayWithTwo[1]}" = "$7" && echo correct
    #
    test "$anotherSingle" = "$8" && echo correct
    #
    test "${table[test]}" = "works"
    table[inside]="adding a new value"
    #
    # I'm using * just in this example:
    test "${anArrayOfVariedSize[*]}" = "${*:10}" && echo correct
}

fourElements=( a1 a2 "a3 with spaces" a4 )
twoElements=( b1 b2 )
declare -A assocArray
assocArray[test]="works"

testPassingParams "first" "${fourElements[@]}" "${twoElements[@]}" "single with spaces" assocArray "and more... " "even more..."

test "${assocArray[inside]}" = "adding a new value"

In other words, not only you can call your parameters by their names (which makes up for a more readable core), you can actually pass arrays (and references to variables - this feature works only in bash 4.3 though)! Plus, the mapped variables are all in the local scope, just as $1 (and others).

The code that makes this work is pretty light and works both in bash 3 and bash 4 (these are the only versions I've tested it with). If you're interested in more tricks like this that make developing with bash much nicer and easier, you can take a look at my Bash Infinity Framework, the code below was developed for that purpose.

Function.AssignParamLocally() {
    local commandWithArgs=( $1 )
    local command="${commandWithArgs[0]}"

    shift

    if [[ "$command" == "trap" || "$command" == "l="* || "$command" == "_type="* ]]
    then
        paramNo+=-1
        return 0
    fi

    if [[ "$command" != "local" ]]
    then
        assignNormalCodeStarted=true
    fi

    local varDeclaration="${commandWithArgs[1]}"
    if [[ $varDeclaration == '-n' ]]
    then
        varDeclaration="${commandWithArgs[2]}"
    fi
    local varName="${varDeclaration%%=*}"

    # var value is only important if making an object later on from it
    local varValue="${varDeclaration#*=}"

    if [[ ! -z $assignVarType ]]
    then
        local previousParamNo=$(expr $paramNo - 1)

        if [[ "$assignVarType" == "array" ]]
        then
            # passing array:
            execute="$assignVarName=( \"\${@:$previousParamNo:$assignArrLength}\" )"
            eval "$execute"
            paramNo+=$(expr $assignArrLength - 1)

            unset assignArrLength
        elif [[ "$assignVarType" == "params" ]]
        then
            execute="$assignVarName=( \"\${@:$previousParamNo}\" )"
            eval "$execute"
        elif [[ "$assignVarType" == "reference" ]]
        then
            execute="$assignVarName=\"\$$previousParamNo\""
            eval "$execute"
        elif [[ ! -z "${!previousParamNo}" ]]
        then
            execute="$assignVarName=\"\$$previousParamNo\""
            eval "$execute"
        fi
    fi

    assignVarType="$__capture_type"
    assignVarName="$varName"
    assignArrLength="$__capture_arrLength"
}

Function.CaptureParams() {
    __capture_type="$_type"
    __capture_arrLength="$l"
}

alias @trapAssign='Function.CaptureParams; trap "declare -i \"paramNo+=1\"; Function.AssignParamLocally \"\$BASH_COMMAND\" \"\$@\"; [[ \$assignNormalCodeStarted = true ]] && trap - DEBUG && unset assignVarType && unset assignVarName && unset assignNormalCodeStarted && unset paramNo" DEBUG; '
alias @param='@trapAssign local'
alias @reference='_type=reference @trapAssign local -n'
alias @var='_type=var @param'
alias @params='_type=params @param'
alias @array='_type=array @param'

Get current directory name (without full path) in a Bash script

For the find jockeys out there like me:

find $PWD -maxdepth 0 -printf "%f\n"

Using await outside of an async function

There is always this of course:

(async () => {
    await ...

    // all of the script.... 

})();
// nothing else

This makes a quick function with async where you can use await. It saves you the need to make an async function which is great! //credits Silve2611

Android - How to achieve setOnClickListener in Kotlin?

Add clickListener on button like this

    btUpdate.setOnClickListener(onclickListener)

add this code in your activity

 val onclickListener: View.OnClickListener = View.OnClickListener { view ->
        when (view.id) {
            R.id.btUpdate -> updateData()


        }
    }

Is the sizeof(some pointer) always equal to four?

if you are compiling for a 64-bit machine, then it may be 8.

Visual Studio Code how to resolve merge conflicts with git?

After trial and error I discovered that you need to stage the file that had the merge conflict, then you can commit the merge.

Renaming files in a folder to sequential numbers

I like gauteh's solution for its simplicity, but it has an important drawback. When running on thousands of files, you can get "argument list too long" message (more on this), and second, the script can get really slow. In my case, running it on roughly 36.000 files, script moved approx. one item per second! I'm not really sure why this happens, but the rule I got from colleagues was "find is your friend".

find -name '*.jpg' | # find jpegs
gawk 'BEGIN{ a=1 }{ printf "mv %s %04d.jpg\n", $0, a++ }' | # build mv command
bash # run that command

To count items and build command, gawk was used. Note the main difference, though. By default find searches for files in current directory and its subdirectories, so be sure to limit the search on current directory only, if necessary (use man find to see how).

database attached is read only

Open database properties --> options and set Database read-only to False.

  • Make sure you logged into the SQL Management Studio using Windows Authentication.
  • Make sure your user has write access to the directory of the mdf and log files.

Did the trick for me...

How to get name of calling function/method in PHP?

The simplest way of getting parent function name is:

$caller = next(debug_backtrace())['function'];

jQuery - selecting elements from inside a element

Why not just use:

$("#foo span")

or

$("#foo > span")

$('span', $('#foo')); works fine on my machine ;)

Pandas sort by group aggregate and column

Groupby A:

In [0]: grp = df.groupby('A')

Within each group, sum over B and broadcast the values using transform. Then sort by B:

In [1]: grp[['B']].transform(sum).sort('B')
Out[1]:
          B
2 -2.829710
5 -2.829710
1  0.253651
4  0.253651
0  0.551377
3  0.551377

Index the original df by passing the index from above. This will re-order the A values by the aggregate sum of the B values:

In [2]: sort1 = df.ix[grp[['B']].transform(sum).sort('B').index]

In [3]: sort1
Out[3]:
     A         B      C
2  baz -0.528172  False
5  baz -2.301539   True
1  bar -0.611756   True
4  bar  0.865408  False
0  foo  1.624345  False
3  foo -1.072969   True

Finally, sort the 'C' values within groups of 'A' using the sort=False option to preserve the A sort order from step 1:

In [4]: f = lambda x: x.sort('C', ascending=False)

In [5]: sort2 = sort1.groupby('A', sort=False).apply(f)

In [6]: sort2
Out[6]:
         A         B      C
A
baz 5  baz -2.301539   True
    2  baz -0.528172  False
bar 1  bar -0.611756   True
    4  bar  0.865408  False
foo 3  foo -1.072969   True
    0  foo  1.624345  False

Clean up the df index by using reset_index with drop=True:

In [7]: sort2.reset_index(0, drop=True)
Out[7]:
     A         B      C
5  baz -2.301539   True
2  baz -0.528172  False
1  bar -0.611756   True
4  bar  0.865408  False
3  foo -1.072969   True
0  foo  1.624345  False

Create a string of variable length, filled with a repeated character

You can use the first line of the function as a one-liner if you like:

function repeat(str, len) {
    while (str.length < len) str += str.substr(0, len-str.length);
    return str;
}

Generate an integer that is not among four billion given ones

Just for the sake of completeness, here is another very simple solution, which will most likely take a very long time to run, but uses very little memory.

Let all possible integers be the range from int_min to int_max, and bool isNotInFile(integer) a function which returns true if the file does not contain a certain integer and false else (by comparing that certain integer with each integer in the file)

for (integer i = int_min; i <= int_max; ++i)
{
    if (isNotInFile(i)) {
        return i;
    }
}

How to add an object to an ArrayList in Java

change Date to Object which is between parenthesis

How do I implement IEnumerable<T>

Why do you do it manually? yield return automates the entire process of handling iterators. (I also wrote about it on my blog, including a look at the compiler generated code).

If you really want to do it yourself, you have to return a generic enumerator too. You won't be able to use an ArrayList any more since that's non-generic. Change it to a List<MyObject> instead. That of course assumes that you only have objects of type MyObject (or derived types) in your collection.

String to decimal conversion: dot separation instead of comma

All this is about cultures. If you have any other culture than "US English" (and also as good manners of development), you should use something like this:

var d = Convert.ToDecimal("1.2345", new CultureInfo("en-US"));
// (or 1,2345 with your local culture, for instance)

(obviously, you should replace the "en-US" with the culture of your number local culture)

the same way, if you want to do ToString()

d.ToString(new CultureInfo("en-US"));

An internal error occurred during: "Updating Maven Project". java.lang.NullPointerException

I had the same problem. None of the solutions here worked. I had to completely reinstall eclipse and make a new workspace. Then it worked!

Get img src with PHP

Use a HTML parser like DOMDocument and then evaluate the value you're looking for with DOMXpath:

$html = '<img id="12" border="0" src="/images/image.jpg"
         alt="Image" width="100" height="100" />';

$doc = new DOMDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$src = $xpath->evaluate("string(//img/@src)"); # "/images/image.jpg"

Or for those who really need to save space:

$xpath = new DOMXPath(@DOMDocument::loadHTML($html));
$src = $xpath->evaluate("string(//img/@src)");

And for the one-liners out there:

$src = (string) reset(simplexml_import_dom(DOMDocument::loadHTML($html))->xpath("//img/@src"));

How to sort a list of strings?

Or maybe:

names = ['Jasmine', 'Alberto', 'Ross', 'dig-dog']
print ("The solution for this is about this names being sorted:",sorted(names, key=lambda name:name.lower()))

Linux command to print directory structure in the form of a tree

This command works to display both folders and files.

find . | sed -e "s/[^-][^\/]*\// |/g" -e "s/|\([^ ]\)/|-\1/"

Example output:

.
 |-trace.pcap
 |-parent
 | |-chdir1
 | | |-file1.txt
 | |-chdir2
 | | |-file2.txt
 | | |-file3.sh
 |-tmp
 | |-json-c-0.11-4.el7_0.x86_64.rpm

Source: Comment from @javasheriff here. Its submerged as a comment and posting it as answer helps users spot it easily.

Python Loop: List Index Out of Range

  1. In your for loop, you're iterating through the elements of a list a. But in the body of the loop, you're using those items to index that list, when you actually want indexes.
    Imagine if the list a would contain 5 items, a number 100 would be among them and the for loop would reach it. You will essentially attempt to retrieve the 100th element of the list a, which obviously is not there. This will give you an IndexError.

We can fix this issue by iterating over a range of indexes instead:

for i in range(len(a))

and access the a's items like that: a[i]. This won't give any errors.

  1. In the loop's body, you're indexing not only a[i], but also a[i+1]. This is also a place for a potential error. If your list contains 5 items and you're iterating over it like I've shown in the point 1, you'll get an IndexError. Why? Because range(5) is essentially 0 1 2 3 4, so when the loop reaches 4, you will attempt to get the a[5] item. Since indexing in Python starts with 0 and your list contains 5 items, the last item would have an index 4, so getting the a[5] would mean getting the sixth element which does not exist.

To fix that, you should subtract 1 from len(a) in order to get a range sequence 0 1 2 3. Since you're using an index i+1, you'll still get the last element, but this way you will avoid the error.

  1. There are many different ways to accomplish what you're trying to do here. Some of them are quite elegant and more "pythonic", like list comprehensions:

b = [a[i] + a[i+1] for i in range(len(a) - 1)]

This does the job in only one line.

Observable Finally on Subscribe

The only thing which worked for me is this

fetchData()
  .subscribe(
    (data) => {
       //Called when success
     },
    (error) => {
       //Called when error
    }
  ).add(() => {
       //Called when operation is complete (both success and error)
  });

getResources().getColor() is deprecated

I found that the useful getResources().getColor(R.color.color_name) is deprecated.

It is not deprecated in API Level 21, according to the documentation.

It is deprecated in the M Developer Preview. However, the replacement method (a two-parameter getColor() that takes the color resource ID and a Resources.Theme object) is only available in the M Developer Preview.

Hence, right now, continue using the single-parameter getColor() method. Later this year, consider using the two-parameter getColor() method on Android M devices, falling back to the deprecated single-parameter getColor() method on older devices.

Set initially selected item in Select list in Angular2

The easiest way to solve this problem in Angular is to do:

In Template:

<select [ngModel]="selectedObjectIndex">
  <option [value]="i" *ngFor="let object of objects; let i = index;">{{object.name}}</option>
</select>

In your class:

this.selectedObjectIndex = 1/0/your number wich item should be selected

What is the significance of url-pattern in web.xml and how to configure servlet?

Servlet-mapping has two child tags, url-pattern and servlet-name. url-pattern specifies the type of urls for which, the servlet given in servlet-name should be called. Be aware that, the container will use case-sensitive for string comparisons for servlet matching.

First specification of url-pattern a web.xml file for the server context on the servlet container at server .com matches the pattern in <url-pattern>/status/*</url-pattern> as follows:

http://server.com/server/status/synopsis               = Matches
http://server.com/server/status/complete?date=today    = Matches
http://server.com/server/status                        = Matches
http://server.com/server/server1/status                = Does not match

Second specification of url-pattern A context located at the path /examples on the Agent at example.com matches the pattern in <url-pattern>*.map</url-pattern> as follows:

 http://server.com/server/US/Oregon/Portland.map    = Matches
 http://server.com/server/US/server/Seattle.map     = Matches
 http://server.com/server/Paris.France.map          = Matches
 http://server.com/server/US/Oregon/Portland.MAP    = Does not match, the extension is uppercase
 http://example.com/examples/interface/description/mail.mapi  =Does not match, the extension is mapi rather than map`

Third specification of url-mapping,A mapping that contains the pattern <url-pattern>/</url-pattern> matches a request if no other pattern matches. This is the default mapping. The servlet mapped to this pattern is called the default servlet.

The default mapping is often directed to the first page of an application. Explicitly providing a default mapping also ensures that malformed URL requests into the application return are handled by the application rather than returning an error.

The servlet-mapping element below maps the server servlet instance to the default mapping.

<servlet-mapping>
  <servlet-name>server</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

For the context that contains this element, any request that is not handled by another mapping is forwarded to the server servlet.

And Most importantly we should Know about Rule for URL path mapping

  1. The container will try to find an exact match of the path of the request to the path of the servlet. A successful match selects the servlet.
  2. The container will recursively try to match the longest path-prefix. This is done by stepping down the path tree a directory at a time, using the ’/’ character as a path separator. The longest match determines the servlet selected.
  3. If the last segment in the URL path contains an extension (e.g. .jsp), the servlet container will try to match a servlet that handles requests for the extension. An extension is defined as the part of the last segment after the last ’.’ character.
  4. If neither of the previous three rules result in a servlet match, the container will attempt to serve content appropriate for the resource requested. If a “default” servlet is defined for the application, it will be used.

Reference URL Pattern

Is there a Wikipedia API?

MediaWiki's API is running on Wikipedia (docs). You can also use the Special:Export feature to dump data and parse it yourself.

More information.

How do I restart a service on a remote machine in Windows?

You can use mmc:

  1. Start / Run. Type "mmc".
  2. File / Add/Remove Snap-in... Click "Add..."
  3. Find "Services" and click "Add"
  4. Select "Another computer:" and type the host name / IP address of the remote machine. Click Finish, Close, etc.

At that point you will be able to manage services as if they were on your local machine.

Unable to open project... cannot be opened because the project file cannot be parsed

If you ever merge and still get problems that dont know what they are, I mean not the obvious marks of a diff

<<<<<
....
======
>>>>>>

Then you can analise your project files with https://github.com/Karumi/Kin, install it and use it

kin project.pbxproj

It has make extrange erros that doesn't allow open the project more easy to understand and solve (ones of hashes, groups and so on).


And by the way, this could also be helpful, thought I have not used it try to diff 2 versions of your project files https://github.com/bloomberg/xcdiff so this will give you really what is going on.

How to make HTML open a hyperlink in another window or tab?

The target attribute is your best way of doing this.

<a href="http://www.starfall.com" target="_blank">

will open it in a new tab or window. As for which, it depends on the users settings.

<a href="http://www.starfall.com" target="_self">

is default. It makes the page open in the same tab (or iframe, if that's what you're dealing with).
The next two are only good if you're dealing with an iframe.

<a href="http://www.starfall.com" target="_parent">

will open the link in the iframe that the iframe that had the link was in.

<a href="http://www.starfall.com" target="_top">

will open the link in the tab, no matter how many iframes it has to go through.

How can I "disable" zoom on a mobile web page?

Possible Solution for Web Apps: While zooming can not be disabled in iOS Safari anymore, it will be disabled when opening the site from a home screen shortcut.

Add these meta tags to declare your App as "Web App capable":

    <meta content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" name="viewport" >
    <meta name="apple-mobile-web-app-capable" content="yes" >

However only use this feature if your app is self sustaining, as the forward/backward buttons and URL bar as well as the sharing options are disabled. (You can still swipe left and right though) This approach however enables quite the app like ux. The fullscreen browser only starts when the site is loaded from the homescreen. I also only got it to work after I included an apple-touch-icon-180x180.png in my root folder.

As a bonus, you probably also want to include a variant of this as well:

<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">

Call method in directive controller from other controller

You could also expose the directive's controller to the parent scope, like ngForm with name attribute does: http://docs.angularjs.org/api/ng.directive:ngForm

Here you could find a very basic example how it could be achieved http://plnkr.co/edit/Ps8OXrfpnePFvvdFgYJf?p=preview

In this example I have myDirective with dedicated controller with $clear method (sort of very simple public API for the directive). I can publish this controller to the parent scope and use call this method outside the directive.

Laravel view not found exception

If your path to view is true first try to config:cache and route:cache if nothing changed check your resource path permission are true.

example: your can do it in ubuntu with :

sudo chgrp -R www-data resources/views
sudo usermod -a -G www-data $USER

Proxies with Python 'Requests' module

The proxies' dict syntax is {"protocol":"ip:port", ...}. With it you can specify different (or the same) proxie(s) for requests using http, https, and ftp protocols:

http_proxy  = "http://10.10.1.10:3128"
https_proxy = "https://10.10.1.11:1080"
ftp_proxy   = "ftp://10.10.1.10:3128"

proxyDict = { 
              "http"  : http_proxy, 
              "https" : https_proxy, 
              "ftp"   : ftp_proxy
            }

r = requests.get(url, headers=headers, proxies=proxyDict)

Deduced from the requests documentation:

Parameters:
method – method for the new Request object.
url – URL for the new Request object.
...
proxies – (optional) Dictionary mapping protocol to the URL of the proxy.
...


On linux you can also do this via the HTTP_PROXY, HTTPS_PROXY, and FTP_PROXY environment variables:

export HTTP_PROXY=10.10.1.10:3128
export HTTPS_PROXY=10.10.1.11:1080
export FTP_PROXY=10.10.1.10:3128

On Windows:

set http_proxy=10.10.1.10:3128
set https_proxy=10.10.1.11:1080
set ftp_proxy=10.10.1.10:3128

Thanks, Jay for pointing this out:
The syntax changed with requests 2.0.0.
You'll need to add a schema to the url: https://2.python-requests.org/en/latest/user/advanced/#proxies

How can I align text directly beneath an image?

This centers the "A" below the image:

<div style="text-align:center">
  <asp:Image ID="Image1" runat="server" ImageUrl="~/Images/opentoselect.gif" />
  <br />
  A
</div>

That is ASP.Net and it would render the HTML as:

<div style="text-align:center">
<img id="Image1" src="Images/opentoselect.gif" style="border-width:0px;" />
<br />
A
</div>

Rails - controller action name to string

Rails 2.X: @controller.action_name

Rails 3.1.X: controller.action_name, action_name

Rails 4.X: action_name

This app won't run unless you update Google Play Services (via Bazaar)

I have found a nice solution which let you test your app in the emulator and also doesn't require you to revert to the older version of the library. See an answer to Stack Overflow question Running Google Maps v2 on the Android emulator.

APT command line interface-like yes/no input?

How about this:

def yes(prompt = 'Please enter Yes/No: '):
while True:
    try:
        i = raw_input(prompt)
    except KeyboardInterrupt:
        return False
    if i.lower() in ('yes','y'): return True
    elif i.lower() in ('no','n'): return False

What is the perfect counterpart in Python for "while not EOF"

You can use below code snippet to read line by line, till end of file

line = obj.readline()
while(line != ''):

    # Do Something

    line = obj.readline()

Invalid length for a Base-64 char array

My guess is that you simply need to URL-encode your Base64 string when you include it in the querystring.

Base64 encoding uses some characters which must be encoded if they're part of a querystring (namely + and /, and maybe = too). If the string isn't correctly encoded then you won't be able to decode it successfully at the other end, hence the errors.

You can use the HttpUtility.UrlEncode method to encode your Base64 string:

string msg = "Please click on the link below or paste it into a browser "
             + "to verify your email account.<br /><br /><a href=\""
             + _configuration.RootURL + "Accounts/VerifyEmail.aspx?a="
             + HttpUtility.UrlEncode(userName.Encrypt("verify")) + "\">"
             + _configuration.RootURL + "Accounts/VerifyEmail.aspx?a="
             + HttpUtility.UrlEncode(userName.Encrypt("verify")) + "</a>";

how to get the first and last days of a given month

Basically:

$lastDate = date("Y-m-t", strtotime($query_d));

Date t parameter return days number in current month.

CSS grid wrapping

I had a similar situation. On top of what you did, I wanted to center my columns in the container while not allowing empty columns to for them left or right:

.grid { 
    display: grid;
    grid-gap: 10px;
    justify-content: center;
    grid-template-columns: repeat(auto-fit, minmax(200px, auto));
}

Parsing JSON from URL

public static TargetClassJson downloadPaletteJson(String url) throws IOException {
        if (StringUtils.isBlank(url)) {
            return null;
        }
        String genreJson = IOUtils.toString(new URL(url).openStream());
        return new Gson().fromJson(genreJson, TargetClassJson.class);
    }

How do I show running processes in Oracle DB?

Keep in mind that there are processes on the database which may not currently support a session.

If you're interested in all processes you'll want to look to v$process (or gv$process on RAC)

Uri content://media/external/file doesn't exist for some devices

Most probably it has to do with caching on the device. Catching the exception and ignoring is not nice but my problem was fixed and it seems to work.

How to export a Vagrant virtual machine to transfer it

My hard drive in my Mac was making beeping noises in the middle of a project so I decided to install a SSD. I needed to move my project from one disk to another. A few things to consider:

  • I'm vagrant w/ virtualbox on a Mac
  • I'm using git

This is what worked for me:

1.) Copy your ~/.vagrant.d directory to your new machine.
2.) Copy your ~/VirtualBox\ VMs directory to your new machine. 
3.) In VirtualBox add the machines one by one using **Machine** >> **Add**
4.) Run `vagrant box list` to see if vagrant acknowledges your machines. 
5.) `git clone my_project`
6.) `vagrant up`

I had a few problems with VB Guest additions.

enter image description here

I fixed them with this solution.

Difference between break and continue statement

Simple Example:

break leaves the loop.

int m = 0;
for(int n = 0; n < 5; ++n){
  if(n == 2){
    break;
  }
  m++;
}

System.out.printl("m:"+m); // m:2

continue will go back to start loop.

int m = 0;
for(int n = 0; n < 5; ++n){
  if(n == 2){
    continue; // Go back to start and dont execute m++
  }
  m++;
}

System.out.printl("m:"+m); // m:4

PowerShell: Run command from script's directory

Do you mean you want the script's own path so you can reference a file next to the script? Try this:

$scriptpath = $MyInvocation.MyCommand.Path
$dir = Split-Path $scriptpath
Write-host "My directory is $dir"

You can get a lot of info from $MyInvocation and its properties.

If you want to reference a file in the current working directory, you can use Resolve-Path or Get-ChildItem:

$filepath = Resolve-Path "somefile.txt"

EDIT (based on comment from OP):

# temporarily change to the correct folder
Push-Location $folder

# do stuff, call ant, etc

# now back to previous directory
Pop-Location

There's probably other ways of achieving something similar using Invoke-Command as well.

Get class name of object as string in Swift

You can extend NSObjectProtocol in Swift 4 like this :

import Foundation

extension NSObjectProtocol {

    var className: String {
        return String(describing: Self.self)
    }
}

This will make calculated variable className available to ALL classes. Using this inside a print() in CalendarViewController will print "CalendarViewController" in console.

Find row where values for column is maximal in a pandas DataFrame

mx.iloc[0].idxmax()

This one line of code will give you how to find the maximum value from a row in dataframe, here mx is the dataframe and iloc[0] indicates the 0th index.

How to export a MySQL database to JSON?

You can export any SQL query into JSON directly from PHPMyAdmin

dbms_lob.getlength() vs. length() to find blob size in oracle

length and dbms_lob.getlength return the number of characters when applied to a CLOB (Character LOB). When applied to a BLOB (Binary LOB), dbms_lob.getlength will return the number of bytes, which may differ from the number of characters in a multi-byte character set.

As the documentation doesn't specify what happens when you apply length on a BLOB, I would advise against using it in that case. If you want the number of bytes in a BLOB, use dbms_lob.getlength.

Using event.target with React components

First argument in update method is SyntheticEvent object that contains common properties and methods to any event, it is not reference to React component where there is property props.

if you need pass argument to update method you can do it like this

onClick={ (e) => this.props.onClick(e, 'home', 'Home') }

and get these arguments inside update method

update(e, space, txt){
   console.log(e.target, space, txt);
}

Example


event.target gives you the native DOMNode, then you need to use the regular DOM APIs to access attributes. For instance getAttribute or dataset

<button 
  data-space="home" 
  className="home" 
  data-txt="Home" 
  onClick={ this.props.onClick } 
/> 
  Button
</button>

onClick(e) {
   console.log(e.target.dataset.txt, e.target.dataset.space);
}

Example

%i or %d to print integer in C using printf()?

%d seems to be the norm for printing integers, I never figured out why, they behave identically.

How to do sed like text replace with python?

[None of the answers works properly above !]

I have a case of multiple key-value replacement in one file around 1000 lines. And after replacement the file structure should keep the same. for example:

key1=value_tobe_replaced1
key2=value_tobe_replaced1
.     .
.     .
key1000=value_tobe_replaced1000

I've tried:

  1. the voted answer from @elmotec for massedit.

  2. answer from @Cecil Curry.

  3. answer from @Keithel.

The three answers definitely helped me a lot but after test I found it costs nearly 40-50s for 1st and 2ed. 3rd is not suitable for multi-replacement so I fixed it.

Notice: refer to the answers before go on.

Here's my code:

Line replacement mode:

start_time = datetime.datetime.now()
with tempfile.NamedTemporaryFile(mode='w', delete=False) as tmp_file:
    with open(abs_keypair_file) as kf:
        for line in kf:
            line_to_write = ''
            match_flag = False
            for (key, value) in tuple_list:
                # print '  %s = %r' % (key, value)
                if  not re.search(patten, line, flags=re.I):
                    continue
                line_to_write = re.sub(r'\$\({}\)'.format(key), value, line, flags=re.I)
                match_flag = True

            if not match_flag:
                line_to_write = line
            tmp_file.write(line_to_write)

shutil.copystat(abs_keypair_file, tmp_file.name)
shutil.move(tmp_file.name, abs_keypair_file)

time_costs = datetime.datetime.now() - start_time
print 'time costs: %s' % time_costs
time costs: 0:00:42.533879

file replacement mode:

start_time = datetime.datetime.now()
with tempfile.NamedTemporaryFile(mode='w', delete=False) as tmp_file:
    with open(abs_keypair_file) as kf:
        text = kf.read()
        for (key, value) in tuple_list:
            text = re.sub(patten, value, text, flags=re.M|re.I)
        tmp_file.write(text)
shutil.copystat(abs_keypair_file, tmp_file.name)
shutil.move(tmp_file.name, abs_keypair_file)

time_costs = datetime.datetime.now() - start_time
print 'time costs: %s' % time_costs
time costs: 0:00:00.348458

So I suggest if you match my case and your file size is not too large you may follow file replacement mode.

How to replace if file size is huge? I have no idea.

Hope this helps.

Provide static IP to docker containers via docker-compose

Note that I don't recommend a fixed IP for containers in Docker unless you're doing something that allows routing from outside to the inside of your container network (e.g. macvlan). DNS is already there for service discovery inside of the container network and supports container scaling. And outside the container network, you should use exposed ports on the host. With that disclaimer, here's the compose file you want:

version: '2'

services:
  mysql:
    container_name: mysql
    image: mysql:latest
    restart: always
    environment:
      - MYSQL_ROOT_PASSWORD=root
    ports:
     - "3306:3306"
    networks:
      vpcbr:
        ipv4_address: 10.5.0.5

  apigw-tomcat:
    container_name: apigw-tomcat
    build: tomcat/.
    ports:
     - "8080:8080"
     - "8009:8009"
    networks:
      vpcbr:
        ipv4_address: 10.5.0.6
    depends_on:
     - mysql

networks:
  vpcbr:
    driver: bridge
    ipam:
     config:
       - subnet: 10.5.0.0/16
         gateway: 10.5.0.1

What to do on TransactionTooLargeException

Add this to your Activity

@Override
protected void onSaveInstanceState(Bundle oldInstanceState) {
    super.onSaveInstanceState(oldInstanceState);
    oldInstanceState.clear();
}

It works for me hope also it will help you

Retrieve specific commit from a remote Git repository

This works best:

git fetch origin specific_commit
git checkout -b temp FETCH_HEAD

name "temp" whatever you want...this branch might be orphaned though

How to get scrollbar position with Javascript?

document.getScroll = function() {
    if (window.pageYOffset != undefined) {
        return [pageXOffset, pageYOffset];
    } else {
        var sx, sy, d = document,
            r = d.documentElement,
            b = d.body;
        sx = r.scrollLeft || b.scrollLeft || 0;
        sy = r.scrollTop || b.scrollTop || 0;
        return [sx, sy];
    }
}

returns an array with two integers- [scrollLeft, scrollTop]

How to use http.client in Node.js if there is basic authorization

From Node.js http.request API Docs you could use something similar to

var http = require('http');

var request = http.request({'hostname': 'www.example.com',
                            'auth': 'user:password'
                           }, 
                           function (response) {
                             console.log('STATUS: ' + response.statusCode);
                             console.log('HEADERS: ' + JSON.stringify(response.headers));
                             response.setEncoding('utf8');
                             response.on('data', function (chunk) {
                               console.log('BODY: ' + chunk);
                             });
                           });
request.end();

How to compare two JSON have the same properties without order?

Lodash isEqual() method is the best way to compare two JSON object.

This will not consider the order of the keys in object and check for the equality of object. Example

const object1={
name:'ABC',
address:'India'
}

const object2={
address:'India',
name:'ABC'
}

JSON.stringify(object1)===JSON.stringify(object2)
// false

_.isEqual(object1, object2)
//true

Reference-https://lodash.com/docs/#isEqual

If sequence is not going to change than JSON.stringify() will be fast as compared to Lodash isEqual() method

Reference-https://www.measurethat.net/Benchmarks/Show/1854/0/lodash-isequal-test

No numeric types to aggregate - change in groupby() behaviour?

How are you generating your data?

See how the output shows that your data is of 'object' type? the groupby operations specifically check whether each column is a numeric dtype first.

In [31]: data
Out[31]: 
<class 'pandas.core.frame.DataFrame'>
DatetimeIndex: 2557 entries, 2004-01-01 00:00:00 to 2010-12-31 00:00:00
Freq: <1 DateOffset>
Columns: 360 entries, -89.75 to 89.75
dtypes: object(360)

look ?


Did you initialize an empty DataFrame first and then filled it? If so that's probably why it changed with the new version as before 0.9 empty DataFrames were initialized to float type but now they are of object type. If so you can change the initialization to DataFrame(dtype=float).

You can also call frame.astype(float)

How do you make sure email you send programmatically is not automatically marked as spam?

Confirm that you have the correct email address before sending out emails. If someone gives the wrong email address on sign-up, beat them over the head about it ASAP.

Always include clear "how to unsubscribe" information in EVERY email. Do not require the user to login to unsubscribe, it should be a unique url for 1-click unsubscribe.

This will prevent people from marking your mails as spam because "unsubscribing" is too hard.

Postgres: How to do Composite keys?

The error you are getting is in line 3. i.e. it is not in

CONSTRAINT no_duplicate_tag UNIQUE (question_id, tag_id)

but earlier:

CREATE TABLE tags
     (
              (question_id, tag_id) NOT NULL,

Correct table definition is like pilcrow showed.

And if you want to add unique on tag1, tag2, tag3 (which sounds very suspicious), then the syntax is:

CREATE TABLE tags (
    question_id INTEGER NOT NULL,
    tag_id SERIAL NOT NULL,
    tag1 VARCHAR(20),
    tag2 VARCHAR(20),
    tag3 VARCHAR(20),
    PRIMARY KEY(question_id, tag_id),
    UNIQUE (tag1, tag2, tag3)
);

or, if you want to have the constraint named according to your wish:

CREATE TABLE tags (
    question_id INTEGER NOT NULL,
    tag_id SERIAL NOT NULL,
    tag1 VARCHAR(20),
    tag2 VARCHAR(20),
    tag3 VARCHAR(20),
    PRIMARY KEY(question_id, tag_id),
    CONSTRAINT some_name UNIQUE (tag1, tag2, tag3)
);

Loop through a comma-separated shell variable

Here's my pure bash solution that doesn't change IFS, and can take in a custom regex delimiter.

loop_custom_delimited() {
    local list=$1
    local delimiter=$2
    local item
    if [[ $delimiter != ' ' ]]; then
        list=$(echo $list | sed 's/ /'`echo -e "\010"`'/g' | sed -E "s/$delimiter/ /g")
    fi
    for item in $list; do
        item=$(echo $item | sed 's/'`echo -e "\010"`'/ /g')
        echo "$item"
    done
}

Writing image to local server

This thread is old but I wanted to do same things with the https://github.com/mikeal/request package.

Here a working example

var fs      = require('fs');
var request = require('request');
// Or with cookies
// var request = require('request').defaults({jar: true});

request.get({url: 'https://someurl/somefile.torrent', encoding: 'binary'}, function (err, response, body) {
  fs.writeFile("/tmp/test.torrent", body, 'binary', function(err) {
    if(err)
      console.log(err);
    else
      console.log("The file was saved!");
  }); 
});

error LNK2001: unresolved external symbol (C++)

That means that the definition of your function is not present in your program. You forgot to add that one.cpp to your program.

What "to add" means in this case depends on your build environment and its terminology. In MSVC (since you are apparently use MSVC) you'd have to add one.cpp to the project.

In more practical terms, applicable to all typical build methodologies, when you link you program, the object file created form one.cpp is missing.

Find if value in column A contains value from column B?

You can try this. :) simple solution!

=IF(ISNUMBER(MATCH(I1,E:E,0)),"TRUE","")

How do you get a directory listing sorted by creation date in python?

Here's my answer using glob without filter if you want to read files with a certain extension in date order (Python 3).

dataset_path='/mydir/'   
files = glob.glob(dataset_path+"/morepath/*.extension")   
files.sort(key=os.path.getmtime)

Correct way to remove plugin from Eclipse

Help --> About Eclipse --> Installation Details --> select whatever you want to uninstall from "Installed Software" tab.

How to change the font color of a disabled TextBox?

NOTE: see Cheetah's answer below as it identifies a prerequisite to get this solution to work. Setting the BackColor of the TextBox.


I think what you really want to do is enable the TextBox and set the ReadOnly property to true.

It's a bit tricky to change the color of the text in a disabled TextBox. I think you'd probably have to subclass and override the OnPaint event.

ReadOnly though should give you the same result as !Enabled and allow you to maintain control of the color and formatting of the TextBox. I think it will also still support selecting and copying text from the TextBox which is not possible with a disabled TextBox.

Another simple alternative is to use a Label instead of a TextBox.

Creating a LINQ select from multiple tables

If the anonymous type causes trouble for you, you can create a simple data class:

public class PermissionsAndPages
{
     public ObjectPermissions Permissions {get;set}
     public Pages Pages {get;set}
}

and then in your query:

select new PermissionsAndPages { Permissions = op, Page = pg };

Then you can pass this around:

return queryResult.SingleOrDefault(); // as PermissionsAndPages

Show git diff on file in staging area

In order to see the changes that have been staged already, you can pass the -–staged option to git diff (in pre-1.6 versions of Git, use –-cached).

git diff --staged
git diff --cached

Format number as percent in MS SQL Server

M.Ali's answer could be modified as

select Cast(Cast((37.0/38.0)*100 as decimal(18,2)) as varchar(5)) + ' %' as Percentage

I just discovered why all ASP.Net websites are slow, and I am trying to work out what to do about it

Just to help anyone with this problem (locking requests when executing another one from the same session)...

Today I started to solve this issue and, after some hours of research, I solved it by removing the Session_Start method (even if empty) from the Global.asax file.

This works in all projects I've tested.

Difference Between $.getJSON() and $.ajax() in jQuery

There is lots of confusion in some of the function of jquery like $.ajax, $.get, $.post, $.getScript, $.getJSON that what is the difference among them which is the best, which is the fast, which to use and when so below is the description of them to make them clear and to get rid of this type of confusions.

$.getJSON() function is a shorthand Ajax function (internally use $.get() with data type script), which is equivalent to below expression, Uses some limited criteria like Request type is GET and data Type is json.

Read More .. jquery-post-vs-get-vs-ajax

Java String to Date object of the format "yyyy-mm-dd HH:mm:ss"

tl;dr

LocalDateTime.parse( 
    "2012-07-10 14:58:00.000000".replace( " " , "T" )  
)

Microseconds do not fit

You are attempting to squeeze a value with microseconds (six decimal digits) into a data type capable only of milliseconds resolution (three decimal digits). That is impossible.

Instead, use a data type with fine enough resolution. The java.time classes use nanosecond resolution (nine decimal digits).

Unzoned input does not fit a zoned type

You are attempting to put a value lacking any offset-from-UTC or time zone into a data type (Date) that only represents values in UTC. So you are adding information (UTC offset) not intended by the input.

Use an appropriate data type instead. Specifically, java.time.LocalDateTime.

Case-sensitive

Other Answers and Comments correctly explain that the formatting pattern codes are case-sensitive. So MM and mm have different effects.

Avoid legacy classes

The troublesome old date-time classes bundled with the earliest versions of Java are now legacy, supplanted by the java.time classes built into Java 8 and later.

ISO 8601

Your input strings nearly comply with the ISO 8601 standard formats. Replace the SPACE in the middle with a T to comply fully.

The java.time classes use the standard formats by default when parsing/generating strings. So no need to specify a formatting pattern.

Date-time objects have no "format"

and I need the resultant date object to be of the same format.

No, date-time objects do not have a "format". Do not conflate date-time objects with mere strings. Strings are inputs and outputs of the objects. The objects maintain their own internal representions of the date-time info, the details of which are irrelevant to us as calling programmers.

java.time

Your input lacks any indicator of offset-from-UTC or troublesome me zone. So we parse as a LocalDateTime objects which lacks those concepts.

String input = "2012-07-10 14:58:00.000000".replace( " " , "T" ) ;
LocalDateTime ldt = LocalDateTime.parse( input ) ;

Generating strings

To generate a String representing the value of your LocalDateTime:

  • Call toString to get a String in standard ISO 8601 format.
  • Use DateTimeFormatter for producing strings in either custom formats or automatically-localized formats.

Search Stack Overflow for more info as these topics have been covered many many times already.

ZonedDateTime

A LocalDateTime does not represent an exact point on the timeline.

To determine an actual moment, assign a time zone. For example noon in Kolkata India comes much earlier than noon in Paris France. Noon without a time zone could be happening at any point over a range of about 26-27 hours.

ZoneId z = ZoneId.of( "Asia/Kolkata" ) ;
ZonedDateTime zdt = ldt.atZone( z ) ;

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How to check if MySQL returns null/empty?

Suppose

$row=mysql_fetch_row($rc)
and if you want to check if row[8] is null then do
$field=$row[8];
   if($field)
echo "";
else
 echo ""; 

How to add a response header on nginx when using proxy_pass?

There is a module called HttpHeadersMoreModule that gives you more control over headers. It does not come with Nginx and requires additional installation. With it, you can do something like this:

location ... {
  more_set_headers "Server: my_server";
}

That will "set the Server output header to the custom value for any status code and any content type". It will replace headers that are already set or add them if unset.

Accessing dict_keys element by index in Python3

Python 3

mydict = {'a': 'one', 'b': 'two', 'c': 'three'}
mykeys = [*mydict]          #list of keys
myvals = [*mydict.values()] #list of values

print(mykeys)
print(myvals)

Output

['a', 'b', 'c']
['one', 'two', 'three']

Also see this detailed answer

Getting number of elements in an iterator in Python

So, for those who would like to know the summary of that discussion. The final top scores for counting a 50 million-lengthed generator expression using:

  • len(list(gen)),
  • len([_ for _ in gen]),
  • sum(1 for _ in gen),
  • ilen(gen) (from more_itertool),
  • reduce(lambda c, i: c + 1, gen, 0),

sorted by performance of execution (including memory consumption), will make you surprised:

```

1: test_list.py:8: 0.492 KiB

gen = (i for i in data*1000); t0 = monotonic(); len(list(gen))

('list, sec', 1.9684218849870376)

2: test_list_compr.py:8: 0.867 KiB

gen = (i for i in data*1000); t0 = monotonic(); len([i for i in gen])

('list_compr, sec', 2.5885991149989422)

3: test_sum.py:8: 0.859 KiB

gen = (i for i in data*1000); t0 = monotonic(); sum(1 for i in gen); t1 = monotonic()

('sum, sec', 3.441088170016883)

4: more_itertools/more.py:413: 1.266 KiB

d = deque(enumerate(iterable, 1), maxlen=1)

test_ilen.py:10: 0.875 KiB
gen = (i for i in data*1000); t0 = monotonic(); ilen(gen)

('ilen, sec', 9.812256851990242)

5: test_reduce.py:8: 0.859 KiB

gen = (i for i in data*1000); t0 = monotonic(); reduce(lambda counter, i: counter + 1, gen, 0)

('reduce, sec', 13.436614598002052) ```

So, len(list(gen)) is the most frequent and less memory consumable

Best way to retrieve variable values from a text file?

Load your file with JSON or PyYAML into a dictionary the_dict (see doc for JSON or PyYAML for this step, both can store data type) and add the dictionary to your globals dictionary, e.g. using globals().update(the_dict).

If you want it in a local dictionary instead (e.g. inside a function), you can do it like this:

for (n, v) in the_dict.items():
    exec('%s=%s' % (n, repr(v)))

as long as it is safe to use exec. If not, you can use the dictionary directly.

No module named 'pymysql'

To get around the problem, find out where pymysql is installed.

If for example it is installed in /usr/lib/python3.7/site-packages, add the following code above the import pymysql command:

import sys
sys.path.insert(0,"/usr/lib/python3.7/site-packages")
import pymysql

This ensures that your Python program can find where pymysql is installed.

jQuery OR Selector?

I have written an incredibly simple (5 lines of code) plugin for exactly this functionality:

http://byrichardpowell.github.com/jquery-or/

It allows you to effectively say "get this element, or if that element doesnt exist, use this element". For example:

$( '#doesntExist' ).or( '#exists' );

Whilst the accepted answer provides similar functionality to this, if both selectors (before & after the comma) exist, both selectors will be returned.

I hope it proves helpful to anyone who might land on this page via google.

Scale iFrame css width 100% like an image

I suppose this is a cleaner approach. It works with inline height and width properties (I set random value in the fiddle to prove that) and with CSS max-width property.

HTML:

<div class="wrapper">
    <div class="h_iframe">
        <iframe height="2" width="2" src="http://www.youtube.com/embed/WsFWhL4Y84Y" frameborder="0" allowfullscreen></iframe>
    </div>
    <p>Please scale the "result" window to notice the effect.</p>
</div>

CSS:

html,body        {height: 100%;}
.wrapper         {width: 80%; max-width: 600px; height: 100%; margin: 0 auto; background: #CCC}
.h_iframe        {position: relative; padding-top: 56%;}
.h_iframe iframe {position: absolute; top: 0; left: 0; width: 100%; height: 100%;}

http://jsfiddle.net/7WRHM/1001/

JS how to cache a variable

You have three options:

  1. Cookies: https://developer.mozilla.org/en-US/docs/DOM/document.cookie
  2. DOMStorage (sessionStorage or localStorage): https://developer.mozilla.org/en-US/docs/DOM/Storage
  3. If your users are logged in, you could persist data in your server's DB that is keyed to a user (or group)

Adding a column to an existing table in a Rails migration

You can also do this .. rails g migration add_column_to_users email:string

then rake db:migrate also add :email attribute in your user controller ;

for more detail check out http://guides.rubyonrails.org/active_record_migrations.html

How to insert an image in python

Install PIL(Python Image Library) :

then:

from PIL import Image
myImage = Image.open("your_image_here");
myImage.show();

How to print React component on click of a button?

I was looking for a simple package that would do this very same task and did not find anything so I created https://github.com/gregnb/react-to-print

You can use it like so:

 <ReactToPrint
   trigger={() => <a href="#">Print this out!</a>}
   content={() => this.componentRef}
 />
 <ComponentToPrint ref={el => (this.componentRef = el)} />

Laravel-5 'LIKE' equivalent (Eloquent)

If you want to see what is run in the database use dd(DB::getQueryLog()) to see what queries were run.

Try this

BookingDates::where('email', Input::get('email'))
    ->orWhere('name', 'like', '%' . Input::get('name') . '%')->get();

How can I change column types in Spark SQL's DataFrame?

the answers suggesting to use cast, FYI, the cast method in spark 1.4.1 is broken.

for example, a dataframe with a string column having value "8182175552014127960" when casted to bigint has value "8182175552014128100"

    df.show
+-------------------+
|                  a|
+-------------------+
|8182175552014127960|
+-------------------+

    df.selectExpr("cast(a as bigint) a").show
+-------------------+
|                  a|
+-------------------+
|8182175552014128100|
+-------------------+

We had to face a lot of issue before finding this bug because we had bigint columns in production.

Android Paint: .measureText() vs .getTextBounds()

The different between getTextBounds and measureText is described with the image below.

In short,

  1. getTextBounds is to get the RECT of the exact text. The measureText is the length of the text, including the extra gap on the left and right.

  2. If there are spaces between the text, it is measured in measureText but not including in the length of the TextBounds, although the coordinate get shifted.

  3. The text could be tilted (Skew) left. In this case, the bounding box left side would exceed outside the measurement of the measureText, and the overall length of the text bound would be bigger than measureText

  4. The text could be tilted (Skew) right. In this case, the bounding box right side would exceed outside the measurement of the measureText, and the overall length of the text bound would be bigger than measureText

enter image description here

How to replace comma (,) with a dot (.) using java

str = str.replace(',', '.')

should do the trick.

Virtual member call in a constructor

I would just add an Initialize() method to the base class and then call that from derived constructors. That method will call any virtual/abstract methods/properties AFTER all of the constructors have been executed :)

Parsing JSON object in PHP using json_decode

If you use the following instead:

$json = file_get_contents($url);
$data = json_decode($json, TRUE);

The TRUE returns an array instead of an object.

C++ - unable to start correctly (0xc0150002)

In my case, Visual Leak Detector I was using to track down memory leaks in Visual Studio 2015 was missing the Microsoft manifest file Microsoft.DTfW.DHL.manifest, see link Building Visual Leak Detector all way down. This file must be in the folder where vld.dll or vld_x64.dll is in your configuration, say C:\Program Files (x86)\Visual Leak Detector\bin\Win32, C:\Program Files (x86)\Visual Leak Detector\bin\Win64, Debug or x64/Debug.

Only using @JsonIgnore during serialization, but not deserialization

In order to accomplish this, all that we need is two annotations:

  1. @JsonIgnore
  2. @JsonProperty

Use @JsonIgnore on the class member and its getter, and @JsonProperty on its setter. A sample illustration would help to do this:

class User {

    // More fields here
    @JsonIgnore
    private String password;

    @JsonIgnore
    public String getPassword() {
        return password;
    }

    @JsonProperty
    public void setPassword(final String password) {
        this.password = password;
    }
}

Adding text to a cell in Excel using VBA

You can also use the cell property.

Cells(1, 1).Value = "Hey, what's up?"

Make sure to use a . before Cells(1,1).Value as in .Cells(1,1).Value, if you are using it within With function. If you are selecting some sheet.

Best way to generate a random float in C#

Here is another way that I came up with: Let's say you want to get a float between 5.5 and 7, with 3 decimals.

float myFloat;
int myInt;
System.Random rnd = new System.Random();

void GenerateFloat()
{
myInt = rnd.Next(1, 2000);
myFloat = (myInt / 1000) + 5.5f;
}

That way you will always get a bigger number than 5.5 and a smaller number than 7.

How to set array length in c# dynamically

Use this:

 Array.Resize(ref myArr, myArr.Length + 5);

MySQL select statement with CASE or IF ELSEIF? Not sure how to get the result

Another way of doing this is using nested IF statements. Suppose you have companies table and you want to count number of records in it. A sample query would be something like this

SELECT IF(
      count(*) > 15,
      'good',
      IF(
          count(*) > 10,
          'average',
          'poor'
        ) 
      ) as data_count 
      FROM companies

Here second IF condition works when the first IF condition fails. So Sample Syntax of the IF statement would be IF ( CONDITION, THEN, ELSE). Hope it helps someone.

How to get first and last day of week in Oracle?

Assuming you mean weeks relative to the first day of the year ...

SELECT first_day_of_week, first_day_of_week+6 last_day_of_week
FROM (
  SELECT TO_DATE(YEAR||'0101','YYYYMMDD') + 7 * (week-1) first_day_of_week
  FROM (
    SELECT substr(yearweek,1,4) YEAR, to_number(substr(yearweek,5)) week
    FROM (
      SELECT '201118' yearweek FROM dual
    )
  )
)
;

How to redirect output to a file and stdout

$ program [arguments...] 2>&1 | tee outfile

2>&1 dumps the stderr and stdout streams. tee outfile takes the stream it gets and writes it to the screen and to the file "outfile".

This is probably what most people are looking for. The likely situation is some program or script is working hard for a long time and producing a lot of output. The user wants to check it periodically for progress, but also wants the output written to a file.

The problem (especially when mixing stdout and stderr streams) is that there is reliance on the streams being flushed by the program. If, for example, all the writes to stdout are not flushed, but all the writes to stderr are flushed, then they'll end up out of chronological order in the output file and on the screen.

It's also bad if the program only outputs 1 or 2 lines every few minutes to report progress. In such a case, if the output was not flushed by the program, the user wouldn't even see any output on the screen for hours, because none of it would get pushed through the pipe for hours.

Update: The program unbuffer, part of the expect package, will solve the buffering problem. This will cause stdout and stderr to write to the screen and file immediately and keep them in sync when being combined and redirected to tee. E.g.:

$ unbuffer program [arguments...] 2>&1 | tee outfile

C++, how to declare a struct in a header file

Okay so three big things I noticed

  1. You need to include the header file in your class file

  2. Never, EVER place a using directive inside of a header or class, rather do something like std::cout << "say stuff";

  3. Structs are completely defined within a header, structs are essentially classes that default to public

Hope this helps!

Linq to SQL how to do "where [column] in (list of values)"

I had been using the method in Jon Skeet's answer, but another one occurred to me using Concat. The Concat method performed slightly better in a limited test, but it's a hassle and I'll probably just stick with Contains, or maybe I'll write a helper method to do this for me. Either way, here's another option if anyone is interested:

The Method

// Given an array of id's
var ids = new Guid[] { ... };

// and a DataContext
var dc = new MyDataContext();

// start the queryable
var query = (
    from thing in dc.Things
    where thing.Id == ids[ 0 ]
    select thing 
);

// then, for each other id
for( var i = 1; i < ids.Count(); i++ ) {
    // select that thing and concat to queryable
    query.Concat(
        from thing in dc.Things
        where thing.Id == ids[ i ]
        select thing
    );
}

Performance Test

This was not remotely scientific. I imagine your database structure and the number of IDs involved in the list would have a significant impact.

I set up a test where I did 100 trials each of Concat and Contains where each trial involved selecting 25 rows specified by a randomized list of primary keys. I've run this about a dozen times, and most times the Concat method comes out 5 - 10% faster, although one time the Contains method won by just a smidgen.

What is a vertical tab?

similar to R0byn's experience, i was experimenting with a Powerpoint slide presentation and dumped out the main body of text on the slide, finding that all the places where one would typically find carriage return (ASCII 13/0x0d/^M) or line feed/new line (ASCII 10/0x0a/^J) characters, it uses vertical tab (ASCII 11/0x0b/^K) instead, presumably for the exact reason that dan04 described above for Word: to serve as a "newline" while staying within the same paragraph. good question though as i totally thought this character would be as useless as a teletype terminal today.

Best way to create a simple python web service

If you mean with "Web Service" something accessed by other Programms SimpleXMLRPCServer might be right for you. It is included with every Python install since Version 2.2.

For Simple human accessible things I usually use Pythons SimpleHTTPServer which also comes with every install. Obviously you also could access SimpleHTTPServer by client programs.

jQuery-- Populate select from json

I believe this can help you:

$(document).ready(function(){
    var temp = {someKey:"temp value", otherKey:"other value", fooKey:"some value"};
    for (var key in temp) {
        alert('<option value=' + key + '>' + temp[key] + '</option>');
    }
});

Setting unique Constraint with fluent API?

Unfortunately this is not supported in Entity Framework. It was on the roadmap for EF 6, but it got pushed back: Workitem 299: Unique Constraints (Unique Indexes)

Splitting a dataframe string column into multiple different columns

We could use tidyr::extract()

x <- c("F.US.CLE.V13", "F.US.CA6.U13", "F.US.CA6.U13", "F.US.CA6.U13", 
  "F.US.CA6.U13", "F.US.CA6.U13", "F.US.CA6.U13", "F.US.CA6.U13", 
  "F.US.DL.U13", "F.US.DL.U13", "F.US.DL.U13", "F.US.DL.Z13", "F.US.DL.Z13"
)


library(tidyr)
extract(tibble(data=x),"data", regex = "^(.*?)\\.(.*?)\\.(.*?)\\.(.*?)$",into = LETTERS[1:4])
#> # A tibble: 13 x 4
#>    A     B     C     D    
#>    <chr> <chr> <chr> <chr>
#>  1 F     US    CLE   V13  
#>  2 F     US    CA6   U13  
#>  3 F     US    CA6   U13  
#>  4 F     US    CA6   U13  
#>  5 F     US    CA6   U13  
#>  6 F     US    CA6   U13  
#>  7 F     US    CA6   U13  
#>  8 F     US    CA6   U13  
#>  9 F     US    DL    U13  
#> 10 F     US    DL    U13  
#> 11 F     US    DL    U13  
#> 12 F     US    DL    Z13  
#> 13 F     US    DL    Z13

Another option is to use unglue::unglue_data()

# remotes::install_github("moodymudskipper/unglue")
library(unglue)
unglue_data(x,"{A}.{B}.{C}.{D}")
#>    A  B   C   D
#> 1  F US CLE V13
#> 2  F US CA6 U13
#> 3  F US CA6 U13
#> 4  F US CA6 U13
#> 5  F US CA6 U13
#> 6  F US CA6 U13
#> 7  F US CA6 U13
#> 8  F US CA6 U13
#> 9  F US  DL U13
#> 10 F US  DL U13
#> 11 F US  DL U13
#> 12 F US  DL Z13
#> 13 F US  DL Z13

Created on 2019-09-14 by the reprex package (v0.3.0)

How to save a plot as image on the disk?

Like this

png('filename.png')
# make plot
dev.off()

or this

# sometimes plots do better in vector graphics
svg('filename.svg')
# make plot
dev.off()

or this

pdf('filename.pdf')
# make plot
dev.off()

And probably others too. They're all listed together in the help pages.

How to detect the physical connected state of a network cable/connector?

Use 'ip monitor' to get REAL TIME link state changes.

Connecting to local SQL Server database using C#

If you're using SQL Server express, change

SqlConnection conn = new SqlConnection("Server=localhost;" 
       + "Database=Database1;");

to

SqlConnection conn = new SqlConnection("Server=localhost\SQLExpress;" 
       + "Database=Database1;");

That, and hundreds more connection strings can be found at http://www.connectionstrings.com/

Duplicate headers received from server

Double quotes around the filename in the header is the standard per MDN web docs. Omitting the quotes creates multiple opportunities for problems arising from characters in the filename.

Colorizing text in the console with C++

You don't need to use any library. Just only write system("color 4f");

Play/pause HTML 5 video using JQuery

Found the answer here @ToolmakerSteve, but had to fine tune this way: To pause all

$('video').each(function(index){
    $(this).get(0).pause();
});

or to play all

$('video').each(function(index){
    $(this).get(0).play();
});

How to run function in AngularJS controller on document ready?

The answer

$scope.$watch('$viewContentLoaded', 
    function() { 
        $timeout(function() {
            //do something
        },0);    
});

is the only one that works in most scenarios I tested. In a sample page with 4 components all of which build HTML from a template, the order of events was

$document ready
$onInit
$postLink
(and these 3 were repeated 3 more times in the same order for the other 3 components)
$viewContentLoaded (repeated 3 more times)
$timeout execution (repeated 3 more times)

So a $document.ready() is useless in most cases since the DOM being constructed in angular may be nowhere near ready.

But more interesting, even after $viewContentLoaded fired, the element of interest still could not be found.

Only after the $timeout executed was it found. Note that even though the $timeout was a value of 0, nearly 200 milliseconds elapsed before it executed, indicating that this thread was held off for quite a while, presumably while the DOM had angular templates added on a main thread. The total time from the first $document.ready() to the last $timeout execution was nearly 500 milliseconds.

In one extraordinary case where the value of a component was set and then the text() value was changed later in the $timeout, the $timeout value had to be increased until it worked (even though the element could be found during the $timeout). Something async within the 3rd party component caused a value to take precedence over the text until sufficient time passed. Another possibility is $scope.$evalAsync, but was not tried.

I am still looking for that one event that tells me the DOM has completely settled down and can be manipulated so that all cases work. So far an arbitrary timeout value is necessary, meaning at best this is a kludge that may not work on a slow browser. I have not tried JQuery options like liveQuery and publish/subscribe which may work, but certainly aren't pure angular.

Best way to work with transactions in MS SQL Server Management Studio

The easisest thing to do is to wrap your code in a transaction, and then execute each batch of T-SQL code line by line.

For example,

Begin Transaction

         -Do some T-SQL queries here.

Rollback transaction -- OR commit transaction

If you want to incorporate error handling you can do so by using a TRY...CATCH BLOCK. Should an error occur you can then rollback the tranasction within the catch block.

For example:

USE AdventureWorks;
GO
BEGIN TRANSACTION;

BEGIN TRY
    -- Generate a constraint violation error.
    DELETE FROM Production.Product
    WHERE ProductID = 980;
END TRY
BEGIN CATCH
    SELECT 
        ERROR_NUMBER() AS ErrorNumber
        ,ERROR_SEVERITY() AS ErrorSeverity
        ,ERROR_STATE() AS ErrorState
        ,ERROR_PROCEDURE() AS ErrorProcedure
        ,ERROR_LINE() AS ErrorLine
        ,ERROR_MESSAGE() AS ErrorMessage;

    IF @@TRANCOUNT > 0
        ROLLBACK TRANSACTION;
END CATCH;

IF @@TRANCOUNT > 0
    COMMIT TRANSACTION;
GO

See the following link for more details.

http://msdn.microsoft.com/en-us/library/ms175976.aspx

Hope this helps but please let me know if you need more details.

Error importing Seaborn module in Python

If your python version is 2.+, you can type below code to the terminal :

pip install seaborn

if python version is 3+, type below:

pip3 install seaborn

PHP CURL DELETE request

To call GET,POST,DELETE,PUT All kind of request, i have created one common function

function CallAPI($method, $api, $data) {
    $url = "http://localhost:82/slimdemo/RESTAPI/" . $api;
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

    switch ($method) {
        case "GET":
            curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data));
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "GET");
            break;
        case "POST":
            curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data));
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");
            break;
        case "PUT":
            curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data));
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PUT");
            break;
        case "DELETE":
            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "DELETE"); 
            curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data));
            break;
    }
    $response = curl_exec($curl);
    $data = json_decode($response);

    /* Check for 404 (file not found). */
    $httpCode = curl_getinfo($curl, CURLINFO_HTTP_CODE);
    // Check the HTTP Status code
    switch ($httpCode) {
        case 200:
            $error_status = "200: Success";
            return ($data);
            break;
        case 404:
            $error_status = "404: API Not found";
            break;
        case 500:
            $error_status = "500: servers replied with an error.";
            break;
        case 502:
            $error_status = "502: servers may be down or being upgraded. Hopefully they'll be OK soon!";
            break;
        case 503:
            $error_status = "503: service unavailable. Hopefully they'll be OK soon!";
            break;
        default:
            $error_status = "Undocumented error: " . $httpCode . " : " . curl_error($curl);
            break;
    }
    curl_close($curl);
    echo $error_status;
    die;
}

CALL Delete Method

$data = array('id'=>$_GET['did']);
$result = CallAPI('DELETE', "DeleteCategory", $data);

CALL Post Method

$data = array('title'=>$_POST['txtcategory'],'description'=>$_POST['txtdesc']);
$result = CallAPI('POST', "InsertCategory", $data);

CALL Get Method

$data = array('id'=>$_GET['eid']);
$result = CallAPI('GET', "GetCategoryById", $data);

CALL Put Method

$data = array('id'=>$_REQUEST['eid'],m'title'=>$_REQUEST['txtcategory'],'description'=>$_REQUEST['txtdesc']);
$result = CallAPI('POST', "UpdateCategory", $data);

How can I handle the warning of file_get_contents() function in PHP?

Since PHP 4 use error_reporting():

$site="http://www.google.com";
$old_error_reporting = error_reporting(E_ALL ^ E_WARNING);
$content = file_get_content($site);
error_reporting($old_error_reporting);
if ($content === FALSE) {
    echo "Error getting '$site'";
} else {
    echo $content;
}

ORACLE and TRIGGERS (inserted, updated, deleted)

I've changed my code like this and it works:

CREATE or REPLACE TRIGGER test001
  AFTER INSERT OR UPDATE OR DELETE ON tabletest001
  REFERENCING OLD AS old_buffer NEW AS new_buffer 
  FOR EACH ROW WHEN (new_buffer.field1 = 'HBP00' OR old_buffer.field1 = 'HBP00') 

DECLARE
      Operation       NUMBER;
      CustomerCode    CHAR(10 BYTE);
BEGIN

IF DELETING THEN 
  Operation := 3;
  CustomerCode := :old_buffer.field1;
END IF;

IF INSERTING THEN 
  Operation := 1;
  CustomerCode := :new_buffer.field1;
END IF;

IF UPDATING THEN 
  Operation := 2;
  CustomerCode := :new_buffer.field1;
END IF;    

// DO SOMETHING ...

EXCEPTION
    WHEN OTHERS THEN ErrorCode := SQLCODE;

END;

Android, How to limit width of TextView (and add three dots at the end of text)?

code:

TextView your_text_view = (TextView) findViewById(R.id.your_id_textview);
your_text_view.setEllipsize(TextUtils.TruncateAt.END);

xml:

android:maxLines = "5"

e.g.

In Matthew 13, the disciples asked Jesus why He spoke to the crowds in parables. He answered, "It has been given to you to know the mysteries of the kingdom of heaven, but to them it has not been given.

Output: In Matthew 13, the disciples asked Jesus why He spoke to the crowds in parables. He answered, "It has been given to you to know...

How do I overload the [] operator in C#

The [] operator is called an indexer. You can provide indexers that take an integer, a string, or any other type you want to use as a key. The syntax is straightforward, following the same principles as property accessors.

For example, in your case where an int is the key or index:

public int this[int index]
{
    get => GetValue(index);
}

You can also add a set accessor so that the indexer becomes read and write rather than just read-only.

public int this[int index]
{
    get => GetValue(index);
    set => SetValue(index, value);
}

If you want to index using a different type, you just change the signature of the indexer.

public int this[string index]
...

Plot multiple boxplot in one graph

Using base graphics, we can use at = to control box position , combined with boxwex = for the width of the boxes. The 1st boxplot statement creates a blank plot. Then add the 2 traces in the following two statements.

Note that in the following, we use df[,-1] to exclude the 1st (id) column from the values to plot. With different data frames, it may be necessary to change this to subset for whichever columns contain the data you want to plot.

boxplot(df[,-1], boxfill = NA, border = NA) #invisible boxes - only axes and plot area
boxplot(df[df$id=="Good", -1], xaxt = "n", add = TRUE, boxfill="red", 
  boxwex=0.25, at = 1:ncol(df[,-1]) - 0.15) #shift these left by -0.15
boxplot(df[df$id=="Bad", -1], xaxt = "n", add = TRUE, boxfill="blue", 
  boxwex=0.25, at = 1:ncol(df[,-1]) + 0.15) #shift to the right by +0.15

enter image description here

Some dummy data:

df <- data.frame(
  id = c(rep("Good",200), rep("Bad", 200)),
  F1 = c(rnorm(200,10,2), rnorm(200,8,1)),
  F2 = c(rnorm(200,7,1),  rnorm(200,6,1)),
  F3 = c(rnorm(200,6,2),  rnorm(200,9,3)),
  F4 = c(rnorm(200,12,3), rnorm(200,8,2)))

Submit button not working in Bootstrap form

  • If you put type=submit it is a Submit Button
  • if you put type=button it is just a button, It does not submit your form inputs.

and also you don't want to use both of these

oracle varchar to number

I have tested the suggested solutions, they should all work:

select * from dual where (105 = to_number('105'))

=> delivers one dummy row

select * from dual where (10 = to_number('105'))

=> empty result

select * from dual where ('105' = to_char(105))

=> delivers one dummy row

select * from dual where ('105' = to_char(10))

=> empty result

How to delete a specific file from folder using asp.net

Delete any or specific file type(for example ".bak") from a path. See demo code below -

class Program
        {
        static void Main(string[] args)
            {

            // Specify the starting folder on the command line, or in 
            TraverseTree(ConfigurationManager.AppSettings["folderPath"]);

            // Specify the starting folder on the command line, or in 
            // Visual Studio in the Project > Properties > Debug pane.
            //TraverseTree(args[0]);

            Console.WriteLine("Press any key");
            Console.ReadKey();
            }

        public static void TraverseTree(string root)
            {

            if (string.IsNullOrWhiteSpace(root))
                return;

            // Data structure to hold names of subfolders to be
            // examined for files.
            Stack<string> dirs = new Stack<string>(20);

            if (!System.IO.Directory.Exists(root))
                {
                return;
                }

            dirs.Push(root);

            while (dirs.Count > 0)
                {
                string currentDir = dirs.Pop();
                string[] subDirs;
                try
                    {
                    subDirs = System.IO.Directory.GetDirectories(currentDir);
                    }

                // An UnauthorizedAccessException exception will be thrown if we do not have
                // discovery permission on a folder or file. It may or may not be acceptable 
                // to ignore the exception and continue enumerating the remaining files and 
                // folders. It is also possible (but unlikely) that a DirectoryNotFound exception 
                // will be raised. This will happen if currentDir has been deleted by
                // another application or thread after our call to Directory.Exists. The 
                // choice of which exceptions to catch depends entirely on the specific task 
                // you are intending to perform and also on how much you know with certainty 
                // about the systems on which this code will run.
                catch (UnauthorizedAccessException e)
                    {
                    Console.WriteLine(e.Message);
                    continue;
                    }
                catch (System.IO.DirectoryNotFoundException e)
                    {
                    Console.WriteLine(e.Message);
                    continue;
                    }

                IEnumerable<FileInfo> files = null;
                try
                    {
                    //get only .bak file
                    var directory = new DirectoryInfo(currentDir);
                    DateTime date = DateTime.Now.AddDays(-15);
                    files = directory.GetFiles("*.bak").Where(file => file.CreationTime <= date);
                    }
                catch (UnauthorizedAccessException e)
                    {
                    Console.WriteLine(e.Message);
                    continue;
                    }
                catch (System.IO.DirectoryNotFoundException e)
                    {
                    Console.WriteLine(e.Message);
                    continue;
                    }

                // Perform the required action on each file here.
                // Modify this block to perform your required task.
                foreach (FileInfo file in files)
                    {
                    try
                        {
                        // Perform whatever action is required in your scenario.
                        file.Delete();
                        Console.WriteLine("{0}: {1}, {2} was successfully deleted.", file.Name, file.Length, file.CreationTime);
                        }
                    catch (System.IO.FileNotFoundException e)
                        {
                        // If file was deleted by a separate application
                        //  or thread since the call to TraverseTree()
                        // then just continue.
                        Console.WriteLine(e.Message);
                        continue;
                        }
                    }

                // Push the subdirectories onto the stack for traversal.
                // This could also be done before handing the files.
                foreach (string str in subDirs)
                    dirs.Push(str);
                }
            }
        }

for more reference - https://msdn.microsoft.com/en-us/library/bb513869.aspx

SQL/mysql - Select distinct/UNIQUE but return all columns?

You're looking for a group by:

select *
from table
group by field1

Which can occasionally be written with a distinct on statement:

select distinct on field1 *
from table

On most platforms, however, neither of the above will work because the behavior on the other columns is unspecified. (The first works in MySQL, if that's what you're using.)

You could fetch the distinct fields and stick to picking a single arbitrary row each time.

On some platforms (e.g. PostgreSQL, Oracle, T-SQL) this can be done directly using window functions:

select *
from (
   select *,
          row_number() over (partition by field1 order by field2) as row_number
   from table
   ) as rows
where row_number = 1

On others (MySQL, SQLite), you'll need to write subqueries that will make you join the entire table with itself (example), so not recommended.

Gradle - Move a folder from ABC to XYZ

Your task declaration is incorrectly combining the Copy task type and project.copy method, resulting in a task that has nothing to copy and thus never runs. Besides, Copy isn't the right choice for renaming a directory. There is no Gradle API for renaming, but a bit of Groovy code (leveraging Java's File API) will do. Assuming Project1 is the project directory:

task renABCToXYZ {     doLast {         file("ABC").renameTo(file("XYZ"))     } } 

Looking at the bigger picture, it's probably better to add the renaming logic (i.e. the doLast task action) to the task that produces ABC.

Format SQL in SQL Server Management Studio

There is a special trick I discovered by accident.

  1. Select the query you wish to format.
  2. Ctrl+Shift+Q (This will open your query in the query designer)
  3. Then just go OK Voila! Query designer will format your query for you. Caveat is that you can only do this for statements and not procedural code, but its better than nothing.

Executing periodic actions in Python

Surprised to not find a solution using a generator for timing. I just designed this one for my own purposes.

This solution: single threaded, no object instantiation each period, uses generator for times, rock solid on timing down to precision of the time module (unlike several of the solutions I've tried from stack exchange).

Note: for Python 2.x, replace next(g) below with g.next().

import time

def do_every(period,f,*args):
    def g_tick():
        t = time.time()
        while True:
            t += period
            yield max(t - time.time(),0)
    g = g_tick()
    while True:
        time.sleep(next(g))
        f(*args)

def hello(s):
    print('hello {} ({:.4f})'.format(s,time.time()))
    time.sleep(.3)

do_every(1,hello,'foo')

Results in, for example:

hello foo (1421705487.5811)
hello foo (1421705488.5811)
hello foo (1421705489.5809)
hello foo (1421705490.5830)
hello foo (1421705491.5803)
hello foo (1421705492.5808)
hello foo (1421705493.5811)
hello foo (1421705494.5811)
hello foo (1421705495.5810)
hello foo (1421705496.5811)
hello foo (1421705497.5810)
hello foo (1421705498.5810)
hello foo (1421705499.5809)
hello foo (1421705500.5811)
hello foo (1421705501.5811)
hello foo (1421705502.5811)
hello foo (1421705503.5810)

Note that this example includes a simulation of the cpu doing something else for .3 seconds each period. If you changed it to be random each time it wouldn't matter. The max in the yield line serves to protect sleep from negative numbers in case the function being called takes longer than the period specified. In that case it would execute immediately and make up the lost time in the timing of the next execution.

filtering a list using LINQ

EDIT: better yet, do it like that:

var filteredProjects = 
    projects.Where(p => filteredTags.All(tag => p.Tags.Contains(tag)));

EDIT2: Honestly, I don't know which one is better, so if performance is not critical, choose the one you think is more readable. If it is, you'll have to benchmark it somehow.


Probably Intersect is the way to go:

void Main()
{
    var projects = new List<Project>();
    projects.Add(new Project { Name = "Project1", Tags = new int[] { 2, 5, 3, 1 } });
    projects.Add(new Project { Name = "Project2", Tags = new int[] { 1, 4, 7 } });
    projects.Add(new Project { Name = "Project3", Tags = new int[] { 1, 7, 12, 3 } });

    var filteredTags = new int []{ 1, 3 };
    var filteredProjects = projects.Where(p => p.Tags.Intersect(filteredTags).Count() == filteredTags.Length);  
}


class Project {
    public string Name;
    public int[] Tags;
}

Although that seems a little ugly at first. You may first apply Distinct to filteredTags if you aren't sure whether they are all unique in the list, otherwise the counts comparison won't work as expected.

What is an unhandled promise rejection?

Promises can be "handled" after they are rejected. That is, one can call a promise's reject callback before providing a catch handler. This behavior is a little bothersome to me because one can write...

var promise = new Promise(function(resolve) {
kjjdjf(); // this function does not exist });

... and in this case, the Promise is rejected silently. If one forgets to add a catch handler, code will continue to silently run without errors. This could lead to lingering and hard-to-find bugs.

In the case of Node.js, there is talk of handling these unhandled Promise rejections and reporting the problems. This brings me to ES7 async/await. Consider this example:

async function getReadyForBed() {
  let teethPromise = brushTeeth();
  let tempPromise = getRoomTemperature();

  // Change clothes based on room temperature
  let temp = await tempPromise;
  // Assume `changeClothes` also returns a Promise
  if(temp > 20) {
    await changeClothes("warm");
  } else {
    await changeClothes("cold");
  }

  await teethPromise;
}

In the example above, suppose teethPromise was rejected (Error: out of toothpaste!) before getRoomTemperature was fulfilled. In this case, there would be an unhandled Promise rejection until await teethPromise.

My point is this... if we consider unhandled Promise rejections to be a problem, Promises that are later handled by an await might get inadvertently reported as bugs. Then again, if we consider unhandled Promise rejections to not be problematic, legitimate bugs might not get reported.

Thoughts on this?

This is related to the discussion found in the Node.js project here:

Default Unhandled Rejection Detection Behavior

if you write the code this way:

function getReadyForBed() {
  let teethPromise = brushTeeth();
  let tempPromise = getRoomTemperature();

  // Change clothes based on room temperature
  return Promise.resolve(tempPromise)
    .then(temp => {
      // Assume `changeClothes` also returns a Promise
      if (temp > 20) {
        return Promise.resolve(changeClothes("warm"));
      } else {
        return Promise.resolve(changeClothes("cold"));
      }
    })
    .then(teethPromise)
    .then(Promise.resolve()); // since the async function returns nothing, ensure it's a resolved promise for `undefined`, unless it's previously rejected
}

When getReadyForBed is invoked, it will synchronously create the final (not returned) promise - which will have the same "unhandled rejection" error as any other promise (could be nothing, of course, depending on the engine). (I find it very odd your function doesn't return anything, which means your async function produces a promise for undefined.

If I make a Promise right now without a catch, and add one later, most "unhandled rejection error" implementations will actually retract the warning when i do later handle it. In other words, async/await doesn't alter the "unhandled rejection" discussion in any way that I can see.

to avoid this pitfall please write the code this way:

async function getReadyForBed() {
  let teethPromise = brushTeeth();
  let tempPromise = getRoomTemperature();

  // Change clothes based on room temperature
  var clothesPromise = tempPromise.then(function(temp) {
    // Assume `changeClothes` also returns a Promise
    if(temp > 20) {
      return changeClothes("warm");
    } else {
      return changeClothes("cold");
    }
  });
  /* Note that clothesPromise resolves to the result of `changeClothes`
     due to Promise "chaining" magic. */

  // Combine promises and await them both
  await Promise.all(teethPromise, clothesPromise);
}

Note that this should prevent any unhandled promise rejection.

Is there a way to suppress JSHint warning for one given line?

Yes, there is a way. Two in fact. In October 2013 jshint added a way to ignore blocks of code like this:

// Code here will be linted with JSHint.
/* jshint ignore:start */
// Code here will be ignored by JSHint.
/* jshint ignore:end */
// Code here will be linted with JSHint.

You can also ignore a single line with a trailing comment like this:

ignoreThis(); // jshint ignore:line

How to initialize an array of custom objects

Here is a more concise version of the accepted answer which avoids repeating the NoteProperty identifiers and the [pscustomobject]-cast:

$myItems =  ("Joe",32,"something about him"), ("Sue",29,"something about her")
            | ForEach-Object {[pscustomobject]@{name = $_[0]; age = $_[1]; info = $_[2]}}

Result:

> $myItems

name           age         info
----           ---         ----
Joe            32          something about him
Sue            29          something about her

How do implement a breadth first traversal?

Breadth first is a queue, depth first is a stack.

For breadth first, add all children to the queue, then pull the head and do a breadth first search on it, using the same queue.

For depth first, add all children to the stack, then pop and do a depth first on that node, using the same stack.

What's the difference between equal?, eql?, ===, and ==?

I would like to expand on the === operator.

=== is not an equality operator!

Not.

Let's get that point really across.

You might be familiar with === as an equality operator in Javascript and PHP, but this just not an equality operator in Ruby and has fundamentally different semantics.

So what does === do?

=== is the pattern matching operator!

  • === matches regular expressions
  • === checks range membership
  • === checks being instance of a class
  • === calls lambda expressions
  • === sometimes checks equality, but mostly it does not

So how does this madness make sense?

  • Enumerable#grep uses === internally
  • case when statements use === internally
  • Fun fact, rescue uses === internally

That is why you can use regular expressions and classes and ranges and even lambda expressions in a case when statement.

Some examples

case value
when /regexp/
  # value matches this regexp
when 4..10
  # value is in range
when MyClass
  # value is an instance of class
when ->(value) { ... }
  # lambda expression returns true
when a, b, c, d
  # value matches one of a through d with `===`
when *array
  # value matches an element in array with `===`
when x
  # values is equal to x unless x is one of the above
end

All these example work with pattern === value too, as well as with grep method.

arr = ['the', 'quick', 'brown', 'fox', 1, 1, 2, 3, 5, 8, 13]
arr.grep(/[qx]/)                                                                                                                            
# => ["quick", "fox"]
arr.grep(4..10)
# => [5, 8]
arr.grep(String)
# => ["the", "quick", "brown", "fox"]
arr.grep(1)
# => [1, 1]

Git submodule head 'reference is not a tree' error

try this:

git submodule sync
git submodule update

Common CSS Media Queries Break Points


@media only screen and (min-width : 320px) and (max-width : 480px) {/*--- Mobile portrait ---*/}
@media only screen and (min-width : 480px) and (max-width : 595px) {/*--- Mobile landscape ---*/}
@media only screen and (min-width : 595px) and (max-width : 690px) {/*--- Small tablet portrait ---*/}
@media only screen and (min-width : 690px) and (max-width : 800px) {/*--- Tablet portrait ---*/}
@media only screen and (min-width : 800px) and (max-width : 1024px) {/*--- Small tablet landscape ---*/}
@media only screen and (min-width : 1024px) and (max-width : 1224px) {/*--- Tablet landscape --- */}